VOL. VIII. No. 9S DECEMBER, 1945

p,op,idorJ: Edilor: TEMPL E PRESS LTD. E . J . GROOM, M . ln s l . Mł:T Dealing Auchoricariveł y with che Produccion, Uses Matta1in1 Diru lor: and Potentialicies of Otf,cu: ROLAND E. DANGERFIELD Lighc Metals and BOWLING GREEN LANE, cheir Alloys , E.C. t

EDITORIAL OPINIO N What! No ?

APPY days they were! Machine sho ps loaded to capaci ty and working day and ni ght, contract departments volubly protesting their absolute inability H to cope with fresh work , rough stores bulgin g with ba r and shcet stock of all ki nds, a co nstant stream of lorries shipping goods away from the finished stores to evcry banie fro nt in the world . They wcre good times. lf a machine broke down o r if the wo rk "s manager wa nted a new ha ndle for the ma ngle, there was always the odd lcngth of m a t e r ia ł lying around- special brasses, sta inless steel, aluminium all oys galo re: now it is all changed . Getting back into peace-timc productio n has brought with it many unexpected problems. Harassed foremcn a nd machine-sho p supcrintendents a re begmning to realize that some of the pleasant ha bits culti vatcd during the war years a re no longer admissibl e. Those pieces of sheet, tubcs, and ofT-cuts from ba rs can no longer be found , ready, like ripe fruit, to be plucked when the occasion dcmands. The luxury of selecting ones pet m a t er i a ł from a n almost limitless variety has now to be forcgone. We a re freq uentl y told that, between the years 1939 .and . 1944 we enjoyed undrea mt of opportunilles fo r beco mmg acqua mted w1th light meta ls, their peculiarities, their virtues, and methods of wo rking. H ow true this is! H ow ou r appreciati ons grew day by day! With what pleasure did we conjure up visions of th e peace-t ime jobs we we re going to execu te in aluminium! Weil, peace is here and , unfortunatel y, many of us have discovc red snags in our day drea ming. When la rge orders come a long, or sho uld we be associated with a big o rganizati on carrying ample stocks, few ditficulties a re likely to a rise when we req uire that small but vital piece of light metal, maybe fo r an unusual mainteaance job, or, poss ibl y fo r some prototype, the responsibility for the ma nufacture of which has suddenl y been thrust upon us by an important clicnt. But the small er manufacturer not organized, perhaps, fo r large-scale buying, often exists (and, in most cases, q uite satisfactoril y), on a hand-to-mo uth basis. Go to any fai r-sized industrial town, Luton o r Watfo rd, for example; there are hundred.s of small facto ries. in and a ro und these arcas, some with machine shops, some w1thout, and 1t 1s qrnte customary, when sheet or rod or tube 1s required to send the boy out to buy. it from the cngineer's sundriesma n around the corner'. Admittedly, choice is somewhat restric ted : brass, o ne or two grades of cH bon steel and sheet can be acquired in this way; but what if d,uring the \'tar years D 578 LI GHT METALS December, 1945 a taste has been acquired fo r aluminium? That taste is li kel y to go unsatisfi ed, for, in gen ęra l , it is, at present, not possible to purchase light all oys in this way. We are not stating here a hypothetical case, but one which has occurred very frequently during the past three or fo ur months and shows _every sign of increasing as existing stocks of light alloy which may remain on manufacturer's premises become exhausted. We hear of small factories reluctantly turning over to cadmium-plated steel for minor lots of wireless chassis. They would rather use aluminium, and have said so quite definitely, hut ca nnot obtain it through their accustomed channels. Brass rod is frequently fo und once again coming back into favour, solely because the aluminium rod which had displaced it during the war years is no longer on tap. Aluminium alloys have become popular in the machine shop, there is no doubt abo ut that, and, in a host of instances, their passing (temporary, we hope) is viewed with the deepest regret. · The storage and sale of aluminium may, we admit, entail careful consideration of some special problems, but it is questionable whether or not in the past these have been viewed in too serious a light. The engineer, in critical jobs requiring the. special brasses, or bronze to tight speci fi catio n, buys these through specific channels. Ordinary yell ow metal, however, was purchased in immense quantities from the small stockist (even from the ironmonger), as also was mild steel or black plate. For holding special grades of aluminium and certain alloys, it is realized that authorized warehouses will stili be required, and, from these, a customer, particularly a small er manufacturer, should be able to requisition his materia), cut, maybe, very close to size in o rd er to ease machining problems and diminish waste. One such warehouse at least should be located in every industrial centre of note, where circumstances permit. It would seem desirable, however, in addition, that the better-eq ui pped engineers' stockist should also be given an opportunity of handling this business, for, in all probability, he has, ready created, a wide market fo r its disposal. In addition, much ~ood m1ght be done by ensunng that the sm31 ll er dealer also held his quota of ordmary grades m the usual fo rms, together w1th, say, an assortment of chili cast rod, tub ~ and section in some of the cheaper and_ mo.re popular secondary alloys. Expen ence has taught us that problems of corros1on m storage.. rarely arise. We have, fo r exa mple, 16 specimens of 18-gauge afuminium sheet, which , between the years 1925 and 1935, were kept, together with brass castings, higgledy­ piggledy, in a bin in the rough stores of a London engi neering wo rks. From 1935 to the present time, they have been living very comfo rta bl y wi th an odd assort­ ment of copper rivets, wire nails and brass washers in an attic next to the wa ter tank. Test pieces of· light-alloy rod have been stored in contact with steel since 1930 in a chicken run. No of any importance has occurred in either instance, but the steel has rusted away. Finally, customers can. as a role, be relied upon to use th eir m a t er i a ł in a sane ma nner.

Contents Pas e Pa ie SPECIAL FE ATU RES Light Metals in t he Food and Allied lndustries 622 Aluminium-alloy Beari ngs 579 Llght-alloy Chassis-cum-Body .. 626 Design for t he lndustry 592 Cerium in light-all oy Technology 630 Two-seater Power Canoe in Light Light-all oy Auto mobil es .. 632 Alloy 597 For Ne w Homes- Why Not REGULAR FEATURES Alumin i um~ ' 607 Ed itorial Opinion 577 New Low-priced C ~r is Mad~ in News - General, Techn ie a l , Aluminium . . 615 Commercial .. 617

•• LIGHT META LS '' is publ,iJied in London, E,.,land , on the /ourth Thu rsda11 of the precedin1 month . SAVE PA PER.-WaJte paper is stili r eąuired to manu/octure i'nlo a thomand /ormJ /or oo r Nau11. Armu arw:l Air Force ouer,eor. December, 1945 LIGHT METALS 579 ALUMINIUM-ALLOY BEARINGS Account after Deck, Neuńausen, on the Development, Prop­ erties, Uses and Advantages oj Aluminium-base Alloy Bearing Materials. T ranslated from "Techniscńe Rundscńau," October ó, 1944, No. 41, and October l 3, 1944, No. 42

YEN prior to 1939, Switzerland, in comparatively low, and this is very common with some other countries, advantageous. Ehad begun the development of bear­ In Fig. I are presented coefficients of ing alloys based on aluminium. Three thermal expansion for various materials, compositions were introduced- La 11 , including cast and steel. Alloy La 21 La 21 and La 31. These three grades has approximately the same coefficient of dilfer in working qualities and in expansion as bronze and is used mainly mechanical and physical properties, and for bearings subjected to shock and high one or other is selected according to ser· load. Il is also employed for metalling vice requirements. cast-iron bearing housings operating at Alloy La 11 consists of aluminium with high temperature. None of these three small quantities of magnesium and zinc; alloys is markedly affected by beating il contains no additions which are not such as is likely to occur in normal readily obtainable in Switzerland. operating ranges. Alloy La 21 is the eutectic aluminium­ Fig. 2 shows hardness of bearing silicon alloy with additions of copper, materials of various types up to 200 nickel, manganese and magnesium; the degrees C. Jt will be observed that hard· copper and nickel contents being about ness decreases to any notable extent only 6 per cent. above 150 degrees C. However, in the Alloy La 31 again consists of alu­ case of aluminium-base bearing metals, minium with about 8 per cent. of tin, plus the deterioration which occurs is by no copper, plus nickel, together with some means so pronounced as that whicb takes magnesium. The medium-hard alloys, place with a tin-base bearing metal La 11 and La 31 , are similar to each (WMSO). The three alloys differ con­ other in possessing good running qualities siderably in their structure. La 21 follows and good resistance to edge pressure. the classical form, showing hard " bear­ Alloy La 31 is preferred to La I I when ing" particles (mainly Si) in a moderately it is impossible to give the bearing surface hard matrix. La 31 , however, exhibits a a high finish and when it is not expedient soft, tin disperse phase in a moderately to run the bearing in gradually under hard matrix, whilst La I I shows the load. homogeneous structure of a solid solu­ lf required, the mechanical properties tion. These physical differences influ­ of these alloys may be considerably ence " bearing" qualities and , according increased by suitable heat treatment, the to the running conditions obtaining, results of wbich may be deduced from account for . occasional trouble due to Table I. Thus it may be seen that the over-heating. greatest strength can be obtained with the La 11 bas little effect on a steel journal, hard bearing alloy La 21 ; the rubbing or whether this Jatter be of the alloy or plain running qualities of this alloy are also carbon type. If by any chance seizing excellent, but its resistance to edge pres­ should occur, a thin layer of aluminium sure is tower than that of the other two will be found adhering to the journal and alloys on account of its greater hardness. can be easily removed. The hard, The thermal expansivity of La 21 is crystalline particles in La 2 t. however, 580 LI GHT METALS December, 1945

Table 1.-Mechanical Propertics of Aluminium Bearing Alloys.

Tensiłe S.G. 0.2% P.~ .. stren&th, Elon ~~ tion, Brin ell tons1sq . 1n. tons sq. in. hardness

1. Cast materia!: 1, 2.7 9.S- 17.4 22 - 28.4 - 12 JS- 45 la 11 { ~~,T : · 23.6-31.6 28.4- 38 - 4 60- 85 28.4-40 30 - 44.S 1 - 3 100- 120 La21 { ~~p - · } 2• { 40 49 43, 49 o.s- 3 120-150 11 - 15.8 22 - 30 3 - 40- SS l11 31 { ~~p -· f 2.85 23.6-35 30 -38 o.s- .3 65 - 80 2. Wrouchtmaterial : 1. 2.7 9.S 14 22 - 30 14 - 22 35- SO la 11 { ~~7 :: 27 - 31 .S 35 -4{) 10 - 15 65- 85

22 -30 31.5-38 2 - 4 80-100 la 21 { ~~.T :· ~ - 2 .8 '\ 46 - 58.S 54 -60 0.2- 1.S 130-150 l a 31 NHT . 2.85 14 - 20.5 25 - 31.S • - 12 45- 60

• Q uali ties recommended . NHT not heu treued. HT hc;it treued.

may in unfavoura ble conditions, score the white metals and special cast , have journal. Tbe tin inclusions in La 31 do, been examined with respect to their bear­ to a great extent, prevent se izing-up ing qualities on a special testin g machin e. occurring with this alloy, particula rly on using forced oil lubrication and a shaft machines of high capacity. Here, if over­ rotating against the specimen to be loading should occur, the bearing surfa ce examined. Test pieces were in the form will remain usa ble for some time, the only of solid bushes 2 ins. internat diameter alteration which occurs being an increase and 4 mm. wa li thickness. The max imum in clearance- a feature which may in permissible loading of a testing machine. certain cases, be of great va lue. 2.6 tons, was not sufficient to cause break­ Aluminium bearings are mainl y down of bearings of the usual lengt h, employed in the form of solid or split na mel y, I t-2t ins. For this reason, speci­ bushes. The materials are supplied in the mens were chosen of about 6.5 mm. long form of wrought rod a nd lube and as in order to permit loading up to 800 sand and chili castings. La 11 and La 31 kg I cm' . Even under !his high loading it can also be produced in the form of cold­ was possible to run some journals at drawn tubes in the usual manner. For 2,000 r.p.m. (corresponding to a surface example, a tube with an outer diameter speed of 1,520 ft. / min .) without trouble : of 2 ins. and about ł in . thick can be an accompanying illustration shows two made to a n accuracy of ± 0.007 in. on bearing rings a nd the shaft after the test inside and outside di a m e ters ~ hence, in (Fig. 6). the case of bea rings with large clearances, For the comparat ive tes t bearings were assembly can be carried out without pre­ fine turned with a diamond and clear­ vious machining. For special purposes, ances were•maintained at a uniform va lue for in stance, as a lining in a suppo rting thro ughout. Temperature on the bening ~i bearing, La 11 ca n be supplied in the surface varied between 100-140 degrees : ł form of sheet o r strip; the cold-worked C„ according to the load, which was li surface, which possesses good " running " increased in stages of 50-100 kg./cm.'. " properties is, obviously, ideall y suited fo r starting from 100 kg. /cm.2 and raised :t a bearing. until either the bearing broke down or ~4 Results of Laboratory Tests the max imum permissible loading of the testing machine was reached. The results o The aluminium-based bearing alloys which have been described, together with of the test are li sted in Fig. 7. The height I ~ a number of bearing bronzes, tin-base of the columns in this diagram corre- December, 1945 LIGHT METALS 581 .,. SO Fig. I. -Linear coefficient of expansion for various bearing materiałs between 20° and I 00°C. : I, ; 2, steel ; 3, bronzc (GBz 12) ; 4. La 21 ; 5, brass ; 6, tin-base white metal (WM 80); 7, La 11 and La 31 ; 8. z inc; 9. lead-base bearing metal (Sn) ; IO, zinc-base bearing metal; 11, laminated plastics ; 12. other plastics (thermal expan­ sivity of 11 and 12 depends on the com- position and treatment of the mate ria!).

regard, the tin-base bearing alloys and most of the bronzes are superio r to the aluminium-base all oys under conditions of optimum lubrication. However, La 21 ""' in this respect has proved superior to La 11 and La 31 . Experience in practice however, has shown that the properties of ·li I aluminium-base bearing alloys are, in t ] ) " 5 7 8 9 JO łl Jl generał, sufficien tl y good for emergency running-in under conditions of poor spond to the average max imum Joad dur­ ing the test. Kg mm' 1t will be seen that the aluminiu:n-base 120 alloys can withstand very high loads, equal, in fact, to those sustained by the 100 two best lead-tin bronzes L and MN. All other bearing materials, including GBzl2 ...... and the tin-base bea ring metal WM 80, eo ...... broke down under loadings of a very much tower order. Despite the fine 60 ~ machining which was given to it, special La 21 cast iron KA 12 proved inferior to the rest of the materials, which demonstrates 40 ~ that the inherent bearing qualities of the r-- La li m a teri a ł are of importance even if the r--- r-- La 11 running surface be scrupulously lubri­ o cated and finished to the highest degree of r-- - r-- WMBO perfection. The tests demonstrate, fur­ 20 50 100 ISO thermore, that the aluminium-base alloys Temperature possess better running-in qualities than any of the bronzes or cast irons Fig. 2.-Hardness of aluminium bearing alloys ( wrought form) and tin-base white ex amined. In thi s regard, however, tin­ metal (WM.80) at ełevated temperatures. base bearing metals remained unsur­ passed. Jubrication. In any case, if the oil film Rapid increase in load a nd careless brea ks down on a highly loaded bearing running-in a re sustained better by the a lu­ surface, rapid heating-up will occur, and, minium-base alloys than by any of the after a short time, the bearing is bound bro nzes examined, this being due, proba­ to be damaged, no matter of what it may bly, to the better cold working properties consist. of the light-metal compositions, their high Subjected to wear against the rough, capacity for oil adsorption and their good hardened surface of a steel shaft under heat conductivity. Without minute conditions of dry friction in a special test­ examination of emergency running-in ing machine, wear values obtained for the qualities, it must be admitted that, in this aluminium-base a lloys were at least as 582 LIGHT METALS December, 1945 good as tbose fo r the best bronzes (L and usefulness of the new inium-bas~ S), and La 21 exbibits even greater wear bearing alloys co uld be judged only by resistance ·than those bronzes. Bronzes the results of practical experience. Actu­ containing higher lead contents (W, Wl 5 ally, a number of concerns have now been using these compositions for so me years with excellent results. Fig. 8 shows two aluminium-base bear­ ings wh ich have been working for IO yea rs, 16 hours a day, and have given no trouble. In this case, eontaet between shaft and bearing is ve ry bad, due to poor adjustment. Although the loading was only 6 kg. / em.2, the real surface pressure amounted to more than three limes this figure. Furthermore, at low speed, the .- .I

(

fig. 3 {above).-Microstructure of La 11. Fig. 4 (right).-Microstructure of La 21. Fig. 5 {below).-Microstructure of La 31. (Equivałent ma gnification in reproduction = X 70 in ałł cases.)

bearings received little lubrication. ln spite of these unfavourable conditions, high pressure at the edges and laek of lubrieation, the assembly has been free running and has eaused no stoppages in a period of 58,000 hours. Three bushes from Swiss State Railway goods wagons supplied by Adolf Saurer . ł ;. ,& ; A.G. are illustrated in Fig. 9. The S.B.B . . ~ "'..·· • .,· ., ,, comments upon its experience of these ··, bushes as follows:- Maximum surfaee ~ < ,f <-' load amounts to a pprox imately 64 kg./em.2 with a surfaee speed of 600 a.od MN) wear out more rapidly tban any ft. i min. The shafts are of mild steel aluminium-base bearing alloy. 55 kg ./ mm.2 U.T.S. For the space of a year now, more tban 300 aluminium Results of Field Tests bushes have been in use, and, more However favourable may be the results reeently, a further 700 have been or are of Jaboratory tests, it was realized thai the being installed. December, 1945 LIGHT METALS 583

did not melt and run as did the white metal. A further test with synthetic-resin bearing compositions showed that these were not suitable for the load and speed in q uestion. Considerable ex- perience has been gained with alu­ minium-base bearing metals in automobile engines, and Adolf Saurer A.G. have for the past three years,

Kg /cm 1 Fig. 6 (above). -Test bearings of La 11 800 " alter 20 hours running under load of 800 kg./sq. cm. at 2,000 r.p.m. ( 1,520 ft. per minute) : 600 A, bearing pressed into housing; B, bearing suńace of test shaft; C, rubbing sutface of a bearin g bush. With the exception of the centre portion, the rubbing surfaces of the bearings 400 have acquired a hi gh polish. Traces of seizing on the shaft are negligible . r'll Fig. 7 (right).-Limits for specific pres- 200 sure of various bearing materials. Fig. 8 (below).-Aluminium-alloy bear­ o ~ ings alter 1O years' use stili in good H .T. H.T. s. L. W.WIS HN. Tl.N (Gaz 12) CAST serviceable condition in spite of poor L.J..11 Ca 21 u Jl BASE IRON CAST BRONZES lubrication and high edge pressure. WM8C KA12

employed an alloy corresponding to La 31 for main bearings and con.-rod bearings in compression-ignition engines. This concem observes that experience in prac­ tice is very good and that aluminium-base alloys will undoubtedly continue to be employed now that the war is finished. _ On account of the high heat conductivity of aluminium-alloy bearings, these have proved suitable for sustaining the very high loads met with in the modern high­ speed high-output engine, where the con- , seąuences of seizure in bearings might be The aluminium-base compositions have very serious. proved superior to bushes with tin-base J unker and Ferber, in Zilrich, have also bearing metal linings, and, so far, no developed aluminium-base bearings inde­ trouble has arisen with undue heating up. pendently of Saurer, and have used them Tests in which the oil supply was cut off in automobile engines of all types. during the run demonstrated the Besides La 31 for main bearings and con.­ superiority of aluminium-base bushes as rod bearings, an aluminium piston alloy, compared to those of bronze with tiń­ similar to_ La 31-Novasil-has been base linings. The aluminium-base alloy used with great success for gudgeon pin 584 LIGHT METALS December, 1945

Fig. 9(1eft).-Aluminium alloy bushes from SBB goods wagons.

Fig. IO(below).-Group of rough turned and finished aluminium alłoy (La 3 1) bearings for automobile engine.

and camshaft bearings. Fig. 10 shows partly turned and finished bushes of La 31 , whilst Fig. 11 shows Novasil connecting-rod bearings. For some years Brown Boveri and Co. have been conducting tests on different bearing materials for Michell bearings in steam turbines; they have selected La 31 as the most suitable alloy. An accompanying illustration shows parts of bearings

Fig. 11 (left).-Connecting­ rod bearings in Novasil for various automobile engmes.

Fig. 12 (below).-Michell beat ings with La 31 plates.

patented by this company. Suitably machined, these bearing segments and cams can withstand Joads up to 900 kg./cm.2 at surface speeds of 6,000 ft. / min., and can, with­ out difficulty, sustain the starting Joads occurring with steam tur­ bines. Unlike other bearing materials, La 31, when breaking December, 1945 LIGHT METALS 585

experienced with them. The load in this case amounts to 4.3 kg ./cm2 at a surface speed of 80 ft.Imin. Lubrication is by means of oil applied to simple drilled holes which are not par­ ticularly dirtproof, or reliable in delivery. The fact that aluminium-base bearing alloys are also suitable for bearings with very little clearance has been proved by their tentative use for main spindle in lathes.

Fig. 13 (left).-La 21 main spindle bearing and tapered shaft of a lathe. Fig. 14 (below).-La 21 bearing lor main spindle fitted to an old lathe. down, will not affect the comparatively soft and polished steel journal even when very heavily loaded; as observed pre­ viously, an aluminium film is formed and may easily be remoyed. The use of La 31 instead of bronze may represent, in this c:ise, a technical advance. A manufacturer of textile machinery has had 250 La 31 bushes in use since March, 1943; no difficulties have been

Fig. 15 (above).-Aluminium bearing lor , rolling mili. Fig. 16 (right).-Grinding machine with three aluminium bearings. E 586 LIGHT METALS December, 1945

a year or 18 months with perfect satis­ faction. Aluminium-alloy bearings have also shown themselves to be suitable for use on electric motors. Quite a number of these units, either run continuously, or

Fig. l 7 (above).-Planing machine with aluminium sliding błock.

Fig. 18 (below).-Cylindricałly bored bear­ ings used in conjunction with a shaft located in an inclined position result in diminished bearing surface (diagram at right) ; by scraping, effective increase in bearing area is obtained (diagram at left). Fig. l 9 (above). - Light slot sections through various surfaces by method of Schmaltz ( X 70) : A, rough turned; B, finish turned; C, fine turned with diamond„

Fig. 20 (below).-Oil groove design and location: A, sharp edges unf avourabłe; B, grooves in areas Fig. 12 shows a bearing in La 21 with o łłoad reduce łoad capacity; C, modern prac.ice its conical shaft. Two bearings of with groove w elł rounded off; D, modern practice with o ił groove in non·loaded portion of bearing; this kind have been in use for more than E, centre zone ring to be used when all available a year, running eight hours daily witb bearing area is loaded.I pressure oil lubrication; no breakdown has occurred. In one workshop the worn main spindle bearings of an old lathe was replaced by an aluminium bearing with drip lubrication (Fig. 13), since then this lathe has been working one and a half years without trouble. It may be seen, according to this experience, that La 21 is well suited to replace the usual bearing bronzes even for main bearings on lathes. A number of further uses are illus­ trated in Figs. 15-17, these show a rolling-mili bearing, and a grinding machine with three aluminium bearings (in this case, lubricated with grease and frequently switched on and off and exposed to highly abrasive swarf). reversed, bave now been operating with Finally there is shown the sliding błock aluminium bearings for well over 12 of a high-speed planing machine also months and no abnormalities have been made of La 21. In every one of these observed. cases the plant has been in operation for In the case of one workshop, many December, 1945 LIGHT METALS 587

Fig. 21 (left).-Bearing design : A. D. long bearinga, large interval between bearinga, Aexible ahaft; theae are factors causing edge preasure; B, modern bearing is short, bearings are placed at closer intervals, shaft is stiffer and edges of bearing are reduced; these faeton make for high loading capacity ; C. long bearings are preferably divided into two aa shown here; E, alternativeły the centre of a long bearing may be relieved as here to in­ crease load capacity; F, rigidly built-in bearings result in edge preasure jf shaft is inclined ; G, modem design of adjustable bearings increasea load capacity.

Fig. 22 (below).-lnRuence of length of bearing on loading capacity (after F alz). Rubbing speed 200 h. per minute.

Tons machine tools, whilst under repair or 2-5 modification, have during the past year / r--.. been fitted with aluminium bearings. '\ The three alloys La 11, La 21 and La 31 I have been employed, lubricated with 1·5 ....._ t"---~ grease or oil and working against shafts j ' in carbon and alloy steels (some merely in the hardened state, others case­ 0·5 I hardened). In this instance, the bearings are all working at temperatures below I o 0·25 0·5 0·75 I 1·25 1·5 1·75 l Ratio ;\- IO 10 30«150 60 70 80 Bear-ing Length in M Ms.

60 degrees c„ and, accordingly, were machined to the same pat­ tern as bronze bearings. In most cases they were fine turned or scraped in the usual manner. To date, their service has been in every way satisfactory. A flywheel bearing 80 mrn. in diameter and 160 mm. long is worthy of special mention. When made of bronze and with

Fig. 23.-Aluminium-alloy bearing bushes for cast-iron houses : A, room temperature, clearance too small. hence, B, bearing siezes; C, bearing at D room temperature with good clearance, c hence D, clearance stili ample when bearing heats up. 588 LIGHT METALS December, 1945

shortly afterwards seized up again, and it is intended to replace this by a similar bearing to La 31. Only a few of many possible examples have been referred to, for a great number of machine constructors have been testing out aluminium-alloy bearings now for some time, Fig. 24 (above).-Alumin­ each under the particu­ ium-alloy bushes fitted in iron housing with tubular lar working conditions spring retainers. called for with respect to this plant. Practical Fig. 25 (right).-Adjacent sketch shows design un­ experience fully confirms favourable to heat transfer, the favourable results whilst sketch at extreme of experimental trials in right shows design favour- the laboratory. able to heat transfer.

Fig. 26 (above).-Aluminium- a łl oy bearing for heavy du ty with minimum oil supply ; the bush expansion keeps the bearing surface well cooled. Fig. 27 (left).-Preloaded bearing with aluminium liner. a ring lubrication system frequent interruptions of service were caused by corrosion. Without any alteration in design, therefore, the same bearing was worked up in La 31 and fitted in as an experi­ ment; it was run 16 to 24 hours a day for over a year without causing trooble. Another bronze bearing fitted later to replace an experimental La 31 bearing

Fig. 28 (above).-Prełoaded bearing with bush of alumin­ ium-base alloy.

Fig. 29 (left). - Preloaded bearing with split bush of aluminium-base a łloy . December, 1945 LIGHT METALS 589

Design Recommendations bear heavier loads than honed or rough­ In any change-over to a new materia], turned surfaces, where comparatively few it is recommended that design and raised points have to bear the whole operating conditions be suitably modified load. By careful and extended running to suit the different properties Jikely to in, such imperfect surfaces can be be encountered with the new material. smoothed and loadability increased. This is especially necessary in the case However, this procedure is in only very of a bearing, and of double importance few instances economical. where such a bearing is heavily loaded. It often happens that bearings cannot A few suggestions have therefore been be precisely located; hence the load may developed. be borne by only a small part of the surface as shown in Fig. 18. In this case Selection of Materiał it is advantageous to scrape the surface, The varying properties of the three thereby considerably increasing the bear­ aluminium-base bearing alloys have ing area. As, however, the degree of already been referred to. These will now smoothness obtained is inferior to that be summarized according to the import­ resulting from diamond turning, maxi­ ance of the alloys in practical use: La 11 mum permissible loading cannot be contains no metals such as tin, copper applied. or nickel, which at the moment are diffi­ Tests with La 11 on the apparatus cult to obtain in Switzerland; it is high referred to in the opening paragraphs of corrosion resistant, exhibits good adsorb­ this paper showed that scraped bearing ing properties for an oil film, and is rela­ bushes broke down under approximately tively low in first cost. 170 kg. /sq. cm., whereas bushes of the La 21 is suitable for vibratory loads, same materia! fine-turned with a diamond has a thermal expansivity similar to that tool withstood loads up to 150 kg. /sq. cm. of bronze; runs well with minimum The machining of aluminium-bearing lubrication, may in emergency continue alloys causes no difficulty, provided that in operation even when strongly heated the correct cutting angles (clearance and up (although in this case the shaft may rake angle) and the correct speed (at least be damaged). 1,250-1,550 ft. per min.) be selected. The La 31 is readily movable, easily run in wedge or cutting angle should be about and resistant to edge pressure, and shows 45 degrees for high-speed steel, and no undue tendency to seize, even with 75 degrees for sintered-carbide tools. minimum lubrication. La 11 and La 31 are readily machined, Shaft materials to run against but La 21 requires some care; the tool aluminium-base-alloy bearings are mild materia! must be of good quality, as La 21 steel of the usual tensile strength, cast contains hard particles. Both La 21 and iron, or (for heavy loads) hardened and La 31 are free cutting. tempered steel or casehardened steel. Lubrication Machining AJuminium-alloy Bearings Any lubricating system is permissible The best results are achieved with with aluminium-alloy bearings, but oil is bearings and shafts of highest surface preferable to grease. Pressure feed in quality. The bearings are fine-turned conjunction with a reliable filter is to be with diamond or sintered-carbide tools, recommended; however, ring or drip employing very small feeds; the journals lubrication are quite suitable. In the last are fine-ground or lapped. Fig. 19 shows case, it is suggested that the oil cup be three different surfaces, the sections being provided with a felt wiek. It is some­ each of the same magnification and times not appreciated that, by leading the obtained by the light-slot method of oil ducts into grooves which expand in Schmaltz (" Technische Oberflachen­ the direction of rotation, it is possible to kunde," Berlin, 1936). It is obvious that obtain what might be described as auto­ a surface fine-turned with diamond can matic pressure lubrication; even if the oil 590 LIGHT METALS December, 1945 supply be situated below the bearing level operating under heavy load or at high the lubrication will be sucked up. temperature must, so far as possible, be According to Buske and Klemencic increased by avoiding edge pressure and ("V.O.I. Zeit.," 1934/8.7 / 409), a vacuum by providing for expansion under beat. of 0.2 to 0.3 atmospheres may be Thus, Fig. 21 shows a number of possi­ recorded under tbese conditions, cor­ bilities, each of which, by itself or in com­ responding to an oil column 3 metres bination with others, results in a safe high; consequently, the bearing coiicerned bearing even under difficult conditions. will never lack sufficient oil. Unfortun­ It may not always be possible to follow ately, for some reason or otber, tbis all these recommendations; in any case, metbod is not often applied. however, modern practice recommends Lubrication witb grease is suitable only that the length of the bearings should not for· smaller loads, especially if the sbaft be excessive, a desirable ratio of length be oscillating. In this case, contrary to to diameter being 0.5: l , reducing the pil lubrication, the load must not exceed length of a bearing to the equivalent of 280 lb./ sq. in. It is recommended tbat, half its diameter will considerably for tbis type of lubrication, a device be increase loading capacity. designed wbicb permits grease to be Falz (" Petroleum," 1931 / 27 / l6) pub­ forced continuously on to the bearing lished an interesting report of his investi­ surface. gations in this connection (Fig. 22). The The Ioadability of bearipgs is greatly loading capacity of long bearings influenced by the arrangements of the oil decreases as a result of edge pressure grooves. In Fig. 20, current practice and caused, first, by bending of the shaft, and, earlier designs are compared. The occur­ secondly, by norma! inaccuracies in the .rence of sharp edges where oil grooves machine base. Narrow bearings, on the intersect the bearing surface binders the other hand, may waste oil at both ends. generation of a coherent oil film ; such Falz succeeded in calculating optimum edges should therefore be well rounded ratios which were in agreement with the off. An oil groove in the loaded part of a results of his tests. lf a long bearing sur­ bearing disturbs the development of an face must be retained it is suggested tbat oil fil:n, hence load-bearing capacity is two separate short units be emplpyed redliced and chances o{ seizing increased. instead of one long one; alternatively, the The loaded part of the bearing should not bearing surface may be recessed in be provided with oil grooves. Bearings the centre (Fig. 21). By either method, that are loaded tbroughout the periphery edge pressure will be greatly reduced . .should be fitted with a central ring groove The recess may be used as a reservoir for for lubrication. lubricant. General Recommendations When a bearing materia[ is fitted into a In most cases, bearings of mmor housing exhibiting small expansion with importance subjected to no. very great heat, correct radia! clearance must be loading can be replaced by aluminium­ applied. Fig. 23 demonstrates how clear­ base alloys withp ut alteratiou. of design, ance changes when operating temperature .that is, provided that the operating tem­ is reached. If clearance be initially too perature does not :exceed , about 60 small, then, sooner or later, the bearing degrees, and, of co4q;e, that lubrication is will seize. As clearance is measured at always suffi cient and ·that· no; chance of room temperature, a certain factor must serious corrosion attacki is Iikely· to occur. be added to account for the different Should these antagonistic faotors arise or expansivity of housing and bearing. lf be suspected to exist, ,then th.e change the bush has a thrust collar, then clear­ .over to aluminiu{Il-all.oy bearh1gs must ance must also be provided for this . be considered ·carefully and,' -if necessary, Numerous suggestions have been made .investigated by special •tests. for the elimination of seizing at the joint The loading capacity of bearings in split ·bearings. The easiest way out of December, 1945 LIGHT METALS the difficu\ty wou\d seem to be to place an arrangement the best possible use is made oil groove at the joint and to round the of the high heat conductivity of alu­ edges. Flexible packing has proved suc­ minium-base bearing alloys to cool the cessful in overcoming difficulties in ther­ bearing surface. mal expansion. To prevent permanent deformation of Putting Aluminium Bearings Into tight-fitting aluminium bushes in heavy Operation metal housings, the following points must It is recommended that oil grooves and be borne in mind: the aluminium-base holes be washed or blown out to remove alloys La 11 and La 31 can be used in the chips, swarf and other foreign bodies. un-heat-treated condition and without Bearing surface and journal should then any special precautions for operating be slightly oiled. If the finish of the bear­ temperatures up to 1OO degrees C. If ing and its fitting are in order, no run­ beat treated, they may be used up to 180 ning-in should be necessary and the degrees C. The limits for La 21 are beuings will be able to work under full higher than these, viz., 170 degrees C. in load immediately. If, however, the bear­ the un-heat-treated condition and 250 ing surface is poorly finished, or if there degrees C. in the heat-treated condition. be any risk of undue edge pressure, then Difficulties of this sort, however, may be careful running-in must be adopted; in avoided by fitting aluminium-alloy bear­ this way bearings may be obtained which ings into light-metal housings. can carry high loads with perfect safety. M ulti-purpose pre\oadability bearings Advantages of High Heat Conductivity by Schmuziger (Riischlikon), for which The beat conductivity of aluminium have been applied, may be fitted bearing alloys is approximately 0.4 cal. / with Little difficulty. As can be seen from cm./ °C., as compared to a figure of 0.13 Fig. 27, the finished bearing consists of for bronze, 0.1 for tiu-base bearing metal a split and flexible steel ring into which and 0.07 to 0.11 for cast iron. Thus fric­ are fitted La 11 bushes. with quite thin tional heat is conducted much more walls. The tolerance on interna! dia-1 readily from the rubbing surface of alu­ meter for diameters of 45 to 60 mm. is minium-alloy bearings than from those of 0.046 mm., that is, 1 per cent. or less of other bearing materials. Such bearings, the diameter concerned. Figs. 28 and 29 therefore, are safer, a point of some show two supporting bearings patented importance where heavy loads are con­ by Brown Boveri. Th!!Y can be used with cerned. However, gaps, insulating shi;ns a solid or a split bush. or openings wh ich interfere with beat flow or transference must be avoided; for Conclusions example, beat flow may be hindered by Aluminium bearing alloys may be con­ an oil film between the two parts of a split sidered as high-grade replacement bearing. Again, to avoid any difficulty materials for metals which a re difficult to with heat transfer, the outer faces of the obtain in Switzerland at the present bushes should be in close contact with the moment. They are not to be considered matching faces of the bearing housing. as " substitutes " in the commonly Fig. 25 compares a good and a bad accepted sense of the word, for, as has design. been showu, they have permitted the Fig. 26 shows a suggestion by Muller, development · of new and improved of Schaffhausen, for. an efficient bearing designs. Tbey have high loading operating with the small quantities of oil capacity, are relatively insensitive to Io.id likely to be provided by a suction system, variation, and are readily run in (if neces­ drip, or wiek lubrication, etc. The sary), have high heat conductivity, are expansion of the bush beyond the bearing light in weight, are readily machilłed, surface by internally milled slots has the show good wear-resistant properties, and effect of fins radiator cooling, especially are not affected by heat developed in if air circulation be provided for. By this running. 59! LIGHT METALS December, 1945

" The spiril of self-reliance is conlinually discouraged; no wonder il grows fainl . Young men reluming from the Forces are to/d thai they are Io have specia/ lraining Io fit them for ' positions ' in the industria/ world and arrangemenls are proposed for lectures, 'courses ' and what not. Very few 'posilions' are wailing for them, but there are any number of ' jobs' for those who seek them di/igently and are prepared Io take off their coals and work their own way Io such 'positions' as they prove themselves capable of holding. And, be il remembered, the besl industrial training co/leges in the world are the workshops and the business offices of our industrial enlerprises-where the hard and inescapable facls of life take the place of more or less nebulous theories."-ALFRED HERBERT.

T Claridges, ?n Thursday,_October 25 , fellows: " Gentlemen, I will now deal with on the occas1on of a reunion luncheon some plain facts known to most of you, but A to members of the committee respon­ which for reasons of etiquette and modesty sible for the first exhibition " Aluminium­ have not been spread abroad. The War to Peace," at Selfridges, G . H. Friese­ aluminium industry is young, and, to expand Greene read a paper on industrial design rapidly in the consumer fields of civil and and designers in relationship to craftsman­ marine architecture, housing, domestic furni­ ship in light alloys and to the aluminium ture and household ware, it must be prepared industry in general. to face hard truths and to hit hard if it Friese-Greene opened his talk by express­ wi shes to capture the home and export ing his pleasure at seeing the committee markets. once again gathered together in the old " Publicly to demonstrate the limitless pos­ friendly and fighting spirit. Especially he sibilities of aluminium was, as we all know, welcomed Air Commodore Helmore, the first and foremost, the purpose of the exhibi­ principal guest, and said that it was the tion at Selfridges, but there were many realistic attitude that the Air Commodore other aims behind this venture which, had taken towards the aluminium industry already, is beginning to bear fruit, but which in his preliminary address as chairman at a undoubtedly would yield a more prolific recent meeting in Burlington House that crop if it were not for influences. which prompted him to speak hard facts to the consciously or unconsciously tend, it seems industry. to me, to break down conficłence in the team He explaine

G 594 LIGHT METALS December, 1945 a bogy. After all, artists have their bad as so well by association that when they design well as their good days, and know only too on paper they see at once a three­ well how easy it is to allow a slightly dis­ dimensional presentation of their work. By cordant note to creep into a design. Artists eye, and without models, they can estimate and designers in industry have, over the war very accurately the weight of sections, period, been harne5sed to the detailing of extrusions or castings required. Again, weapons of destruction in all their forms. It within my own organization, mistakes are Is to be expected that, for some little time seidom made for neither we, nor anybody yet, their style may be cramped, for their else, can afford errors. You can tear up a inspiration has suliered. For goodness' sake drawing, gentlemen, but yo u cannot tear -encourage them! down a six-story building. " It is axioffiśltic that, no matter what may " Most people of culture are, in one form be the structure in which you are in.terested, or another, artists, and the masses in general or upon which you are engaged, every effort will be found to possess submerged artistic should be made for the realization of feelings merely waiting for stimulus to pro­ serviceability, simplicity and truth. In many voke them to activity. That is why the instances, decoration will be called for, standard of design can be raised immediately may be fo please the client or to blend to a and exploited for its selling value in mass period in design, to harmonize with an production, particularly for ex port. environment or to tell a story. But, in " Good taste in design is acquired through decoration or enrichment, every effort should education, amongst the most important be made to avoid discord, and often this is aspects of which, for our purpose, may be not quite so si mple as it may appear. As considered culture, tradition, and association. far as possible, given good functional form Fundamental improvement in standards of and pleasing proportions in a structure, design amongst the masses of our people reliance should be plac~d on the inherent must rest with the Board of Educati on, for beauty and natura! finish of the materia! the surest foundations are to be laid when employed. the subject is very young. These are points. "For good designs these are simple laws however, that we may well leave here to our and must be obeyed, although, paradoxically educational experts anct to the sociologist. enough, the simpler forms, to be really good, " The aluminium industry is interested in a re generally more difficult and more expen­ the realm of art and must continue so to be, sive to make. It is cheaper to hide a joint for there lies real progress and the true by a rosette than by precision craftsmanship, path of commercial development. Deville but if this practice be adopted, at least !et recognized this nearly a hundred -years ago. the rosette be designed for the article and It is only through the arts that aluminium not just a stock pattern. Sometimes it is can be established in tradition. In applying easier to make a joint a feature than to hide the correct scientific method and technique it altogether. So you see, by example, for the solution of its problems, the aircraft how essential it is that industrial design and industry, in the use of high-strength alloys those who practise it must face up of aluminium, has approached the fine a rts. truthfulJy to reality. It is the designer's What can be more beautiful to the eye than duty to satisfy his customer at the right price. some of our !atest fighters? But it is in If he does so and, at the same time, ra ises performance that we see them in their fullest ·the standard of taste, he will at least have glory. Here we have form and purpose, the achieved something. keynote in all industrial design, however " To assist design on articles for quantity la rge, however small , however complicated, production models and prototypes should be however simple the unit. made. Such a course will entail the expendi­ " Scientists and technicians are generall y ture of time and money, heavy expenditure modest about the beauty of their achieve­ maybe, but it will he well worth while. In ments, but they know- for the search for my owo company we specialize in a great truth in de.;ign brings beauty. lf onl y the variety of prototypes covering many scientists' societies would occasionall y open industries, and the form values have to be up their meetings for di sc ussions on the adapted for the industrial machine. In my philoso phy of a rt and sc ience as applied own experience, clients have ha rdly ever to new materials (maybe for talk s on the regretted the initial expenditure, although a philosophy of those new materials them­ momentary groan may escape them when selves), there would be a more generał and they receive the bill. scientific appreciation from all raw-material " Industrial designers know their materials producers in the design and destinati on of December, 1945 LIGHT METALS 595

those of lheir wares destined for the con· every possible sphere of decorative work. sumer markets. Internally one big chemical " It does not take long for good craftsmen, company has already taken the lead: it was fitters, welders, machinists and polishers to delightful to listen to the chairman of l.C.l., learn to manipulate aluminium without Ltd. (Plastics Division), speaking at a recent scratching or denting the sutface. lts light· meeting wllh quiet confidence on the future ness and ease in handling are distinct of · Perspex ' in science and art. advantages in construction compared with " Possibly the nearest approach to good the much heavier group of metals, so decorative art that the aluminium industry fabricators new to light alloys need not fight has achieved over here are the murals shy of introducing them into their shops; · telling the story of aluminium' and first they will soon revel in them as we do! shown during the exhibition at Selfridges " I look forward to the time when (see 'Light Metals,' July, pp. 336-337). creative artists can fee! and live aluminium For these, the industry is indebted to the as we do, although creativeness is not brilliance of the architect and mural artist, exclusive to the skilled artist on paper or Ralph Lavers. He would n·ot wish it to be canvas. Be true to yourself, true to your forgotten that the finał result was achieved materiał and use your imagination as it was by a team of industrial designers, technicians, meant to be nsed, then, having done these detailers and craftsmen working as an things, respect simplicity, and any one of you harmonious whole. The re was full can produce a work of art in light metal. sympathy and purpose throughout, just as Only when the creative artist or sculptor there must always be when interpreting thinks aluminium, only when he is architects' designs. thoroughly steeped in the knowledge and " Ralph Lavers's mural designs were experience of its properties and has himself carried out meticulously, line for line, with transcended artisanship to t r a n s m u t e character and precision, although it should abstract beauty into a dimensional form will be recorded that the form of display, con· you get creations in light metal which justify struction, and the working technique were a f)iche in the realm of pure art. I wonder conceived within industry itself-with the if this will be pos~ible by June next year, in industrial designers and the craftsmen time for the nat1onal exhibition? I hope actually doing the job. This example of the Aluminium Development Association inspiration and team work was made will not be found wanting either in the possible by mutual understanding and searching or in the inspiration. respect. Sometimes it is not sufficiently " Of the Selfridge exhibition, in connection a ppreciated how important it is to inspire, with which most of us on the committee maintain and protect confidence in every worked and fought, I really have quite a lot member of a team if really good work is to say without even mentioning the words­ to be produced; the slightest destructive rhythm, subtlety, form, or the bill at the end criticism while the job is in progress will of it all. The exhibition was a success far assuredly affect the fina! result. Craftsmen beyond the dreams of those not in close know that, to achieve their best, they musi touch with the deliberations of the com· pul their very soul inio their work. They mittee. After all, the in terests and the do not just exist hecause of it. pockets of trade and commerce were well " I well remember visiting the blacksmith's represented, with industrialists, scientists, shop whilst they were forging the decorative technicians, super salesmen, organizers, window grille exhibited at Selfridges, and display artists, journalists and others, all out hurriedly mentioning that it would be good to one end, to sell the aluminium idea. to introduce a snail to fit a small space in " As was intended, • the architect and the design. Next morning, sure enough, constructional engineer visiting the exhibi· there, crawling along the anvil, was a live tion soon absorbed the potentialities of the snail, and, beside it, a forged reproduction in metal for progressive design, for they saw aluminium, formalized to blend to the details with an observant eye, a trained mind pattern. This decorative grille was repro· and practised hands. Judging by personal duced in aluminium to indicate the extreme inquiries, the exhibition in all its reality and malleability of the metal in the hands of the versatility has more than impressed fabri· blacksmith e m p I o y i n g his traditional cators. It has certainly stirred the public. technique, but the smith soon learned to "If l may presume for a moment: I enjoy the forging of a delicate tracery in believe that the time is now opportune for aluminium for other exhibits, exemplifying the personality of a good architect to be felt more natura! applications of the materia! in at the exhibition on tour, in planning display 596 LIGHT METALS December, 1945 and adding new exhibits. lndustry has told a million skilled operatives used to working its first story and the architect's presence at and handling aluminium. It was therefore this stage would prepare ~he aluminium realized that a healthy and versatiie demanci industry for the national effort next year. for light metals would have to be created For the office· in question, however, an right speedily. authority of the highest standing must be " MY. own company was approached to selected. lt is now the concern of architects for~ a team to conceive, design, and produce and designers all over the country to begin exhibits worthy of aluminium and of the to tell their story in aluminium and a mighty occasion. Very few knew the real difficulties. story it will be, if the Association enlist Government inspectors had to be induced to ' super-salesmen ' of the right order and give cultivate the " Nelson " eye, and, with the them the right job to do. men, all the prickly problems of post-war " May I please add a little advice: lf production loomed up at one fell swoop. fabricators be approached for the execution Finally, the works themselves were clogged of special exhibits, competition should be with war materiał. cut out, for your architect will see that you " Anyway, the si tuation was understood. get value for the amount you spend. Times and, eventually, the wholehearted co-opera: are difficult for production, and fabricators tion of the entire organization was enlisted are important to the industry; they must be in the effort. l just do not want you to encouraged to use aluminium now- not forget what those men did, nor what was to-morrow or the day after. Here l am not done by those of the Northern Aluminium referring merely to my own company, for Co., Ltd., British Aluminium and other com­ ·we are but one of a world-wide guild of panies which supplied the materiał to time. craftsmen of incredibly ancient lineage. We The rest most of you know. lt was team all began with bronzc and wrought iron, and work everywhere with spl endid leadership by in this generation we shall probably finish our chairman, Mr. Jones. Special praise with magnesium. Anyhow, the traditional must be given to Selfridges for producing the metals will not envy you nor us: it is a masterly plan of the exhibition itself, and delight to work in them all. However, it for their untiring enthusiasm. Nor should is important that your pioneer work in we forget the trials of Alumilite and Alzak, aluminium be carried out by the very best Ltd., which concern, within a matter of of craftsmen, and cut prices do not ease the weeks, days, sometimes hours, executed vast situation. Finally, competition in art is amounts of {>Olishing, anodizing and dyei ng always false economy. You will probably for the numerous special exhibits. recall the story of Cellini, who, finding him­ " Gentlemen, in the e x h i b i t i o n, self ·short of metal when casting a statue, ' Aluminium-War to Peace,' at Selfridges. tipped in the pelty cash. You want the you succeeded in your aims. In the domestic craftsman's very best work for your exhibits field you stimulated not only interest but next year? Then give him time to do it. constructive thought: results of the kitchen The hours are slipping by. ware quiz give good indication of this. "Now, how and why was the Selfridge From the public itself carne fresh ideas from exhibition a success? Tt was so because the which, in a matter of hours, new designs committee responsible to so large an extent were produced. In the field of generał for its organization was composed of engineering you did, in the ' Story of realists, and, as such, they wanted action. Fabrication,' successfully encourage the They knew that with aluminium 'seeing is structural engineer, the consultant, and the believing.' In their realism they wanted the experts dealing with otlter materials to think best they could get in the shortest time, in terms of aluminium. In the field of although, with the war in Europe sti li in industrial art and architecture you made the progress, production conditions were far task of the craftsman easier in the promoting from favourable. How could it be done? of materials which all of us know to be good. lf, in spite of prevailing conditions there This is not wishful thinking. There is a were to be an exhibition worthy of the glorious hi story ahead for li ght metals here, industry, the public had to see the real and everywhere; make no mistake about material- not just stick , plaster and photo­ that! graphs. And why was the whole matter of " The aluminium industry has sown tbe such vital urgency just then? Because it was seeds for a great nationat effort next year. a mora] and a national issue. At that time l wish you well. Vigour of purpose and it was known that there woutd soon be a alertness of mind- the materi a ł will do the need to re-absorb from the aircraft industries rest." December, 1945 LIGHT METALS 597 Two-Seater POWER CANOE IN LIGHT ALLOY Presenting a Brief Note on the History and Development of a Special Light-metal Boa! Incorporating Many Novel Fea­ tures. A Complete Speciftcation is Included in the Account

AT some time during the course of the stern sections beiag removable. Con­ war it appears that the Services called struction was in łs -in. plywood with a for -the construction of a special boat mahogany keel. Unfortunately, for for a purpose which, Ofl grounds of tropical conditions, the use of wood in this security, was ńot made public. It was way proved unsuitable, and the Warwick required that this boat should be easily Aviation Co., Ltd., was now approached transported by hand and should be and asked to design a model in Birma­ capable of standing up to very heavy bright. In the execution of the metal weather. boat, other concerns, including Aldous The request having gone forth, an Successors, Ltd., participated. assortment of brains, technical skill, and This particular alloy was selected craftsmanship was mustered, and eventu;. principally on account of its very high ałly a hard-chine wood prototype canoe resistance to corrosion, even under marine on the Catamaran principle was evolved. conditions, and because, in addition, it lt was soon discovered, however, that this exhibits the necessary high mechanical design was too large to be handled con­ strength. On the Birmabright assembly a veniently; a further model, therefore, was special bow was designed with a particu­ designed, with a round bilge, bow and larly high sheer a nd wide flare, features

HOWN here, and at the head of the following page, are two views of the S boat described in this account. Note particularly the stern and rudder design. (Courtesy Warwick Aviation Co., Ltd.) 598 LIGHT METALS December, 1945

which played a very large part in giving lgnition, B.l:;. H. magneto. the boat such sea-going qualities. Starting, by handle from aft cockpit. 1. Dimensions. Petrol tank capacity, lt gallons. Oil sump capacity, I pt. Length (overall), 18 ft. O in. Carburetter, Solex. Length (how section), 5 ft. O in. Length (centre section), 8 ft. O in. 4. Propeller. Length (stern section), 5 ft. O in . Number of blades, 3. Beam, 2 ft. 1t ins. Diameter, 8 ins. Width over catamarans, 4 ft. 7 ins. Pitch, 7 ins. Depth (from gunwale to underside keel), 1 ft. li ins. 5. Performance (at full throttle). Depth (from C / L deck to underside Speed, 7.75 knots, 8.9 m.p.h. keel), 1 ft. 3! ins. Petrol consumption, 3 pts. per hr. Draught, 6 ins. Range on It -gallon tank, 35.6 miles, 2. Weights. 4 hrs. Range per galion, 23 .7 miles, 2 hrs. Complete with all gear, oil and petrol, 39 mins. 270 lb. Propeller efficiency, 67.25 per cent. Complete without oil and petrol, Propeller slip, 32.75 per cent. 229 ł lb. Bow section, 26 ł lb. 6. Gear. Centre section, 63t lb. Double-bladed paddles, 2. Stern section, with rudder (less oil and Waterproof seat cushions, 2. petrol), 105t lb. Waterproof cockpit canopies, 2. Catamarans (2), 34 lb. Waterproof cockpit covers, 2. 3. Power Unit. Mast apron, 1. Mast, sail and yard; with halyard and Manufacturers, Norman Engineering tack down, 1 set. Co., Ltd., Warwick. Slings, 2. Type, horizontally opposed, twin cylin- Painters, 2. der, four-stroke T.300. C.Q.R. anchor and line, I. Capacity, 296.56 c.c. Fire extinguisher, I. Cooling, air. Bilge pump, I. R.p.m. at full throttle, 2,000. Engine tools and spares, 1 set. B.h.p. (at 2,000 r.p.m.), 3. Petrol consumption (at 2,000 r.p.m.), 7. Generał Specification.-(a) Materiał. 1 pt. per b.h.p.-hr. The materiał used is mainly Birma­ Oil consumption, 1 pt. per 20 hrs. bright, an aluminium-magnesium alloy Lubrication, gear pump. which combines high mechanical strength Oil pressure, 30 lb./sq. in. with a weight one-third that of steel and December, 1945 LIGHT METALS 599

f URTHER view of the power canoe which, at the foot of page 604, is seen in its dismantled form. (Courtesy Warwick Aviation Co., Ltd.) an exceptionally high resistance to sea­ painter eyes and mast stop being die­ water corrosion. M.G.5 rivets have been stampings in the same materiał. used throughout, together with Duralac All bow and stern attachment fittings for all joints. For fittings which have are of high-grade stainless steel, together called for additional strength, stainless with the brackets mounting the outrigger steel, together with bolts of the same locks; all bolts, screws and nuts securing materia!, have been used, and where it these items are of the same materiał. has been necessary to use bronze fittings 8. Noteworthy Features.-(a) these have been insulated from the Quick Release Attachment for Birmabright with thin fibre sheet to Bow and Stern. reduce the risk of electrolytic action. All sheet Birmabright is to specification The advantages of the above will be B.B.3, excepting the centre section skin; appreciated readily, since it makes the this is to specification B.B.5, the higher detachment of the bow and stern from magnesium content giving greater tough­ the centre section a matter of seconds, ness and strength. simply by removing two pins in each case, Both bow and stern section skins, thus dividing the canoe into three sec­ together with the Catamaran skins, are tions, convenient for handling, transit or of 20.G., each being fabricated in two stowage. halves with a central welded seam. The The pins are permanently made fast to centre section skin is of 22.G. in one the bow and stern sections, to obviate loss piece. when unassembled, and upon assembly are positively locked in position as a pre­ (b) Construction. caution against working out under All frames are of a strong section and, buffeting. together with bulkheads, deck beams, Every care has been taken, both in stringers, deck stiffeners, decking, bilge design and fitting, to ensure that the keels and seats, are of 20.G. fittings are not only adequate but more The main keels are of J6.G., those for than strong enough to cope with all bow, stern and centre sections being of norma! conditions. channel section, and for the catamarans of a swaged section. (b) Patent Watertight Hatches on Bow The yoke and rudder are mainly of and Stern. 18.G. and of welded and riveted con­ The hatch design, forming an efficient struction. breakwater, has the advantages of sim­ The outrigger slides are of 16.G. and plicity, watertightness and a pleasing 12.G ., the outriggers themselves being of appearance. 1-in. by ł-in. ftat stock, while the body The universal hinge permits the cover of the outrigger locks is a Birmabright to be raised in the norma! way or to be casting. swung back horizontally to elear the All cleats are cast Birmabright, the (Conlinued on p. 604. ) 600 LIGHT METALS December, 1945 December, 1945 LIGHT METALS 601

LIGHT-ALLOY POWER CANOE

BOVE. - Centre sec­ BOVE (left).-Centre tion, plan view, prior section, showing keel A A to decking. Below (right) and keelsons. (Right) Aft Centre section, aft view, section prior to decking. prior to decking.

EFT.-Bow section Lcomplete, w at er - tight hatch closed. Below {right) Cata­ m ar a n pn or to decking. 602 LIGHT METALS December, 1945

A BOVE, left : Bow section prior to decking. Above, right: Bow section showing J-\ keel. Belo w: Aft section showing keel and rudder post. December, 1945 LIGHT METALS 603

ABOVE : centre section. f--\. Detail of bulkhead, main frame, a nd outrigger beam.

EFT : Aft section, L sh owing attachment of rudder post.

IGHT : Cen­ R tre section complete, three­ quarter forward view. 604 LIGHT METALS December, 1945

(Text continued from p. 599.) A suction-type bilge pump is fitted on hatch opening, giving access to the stow­ the decking, in such a position between age space in the bow and the engine the two cockpits that it may be conveni­ compartment in the stern section. ently operated from either. The suction Watertightness is effected by the closure hose is sufficiently long to enable the stern of the cover on to a rubber seating by section to be pumped out. means of two quickly operated catches. The mast yard and sail are stowed on (c) Bow Section. either side of the decking and secured by rubber straps, t~e C.Q.R. ancbor being The deck lines of the flared how are similarly secured immediately forward of noticeable, the combination of flare and the mast deck ring. The latter is rendered sheer tending to keep down spray, at the watertigbt by a rubber cap when the mast same time preventing burrowing when is not stepped. running with a following sea. The catamarans are mounted on out­ For ease of access to the stem to carry riggers, which run in slides mounted out any necessary repairs, a handhole and athwart eacb end of the centre section. cover are provided on the decking, the The outriggers are locked when the cata­ remainder of the how section being marans a re in tbeir outboa rd positions, readily accessible through the hatch. of which there are two; fully extended (d) Centre Section and Catamarans. when under power or sail, and closer in Apart from the two cockpit openings when paddling. Each pair of locks is con­ the centre section is completely decked, trolled by one wire, which when pulled and two seats, Jltted with waterproof unlocks the outriggers; each catamaran cushions, are provided. The accommoda­ may then be slid inboard, stowed on top tion is such that there is a mple leg-room of the decking and locked in position, for the two occupants, each being pro­ thus facilitating handling and transport. vided with a waterproof canopy, the Each catamaran is filled with table­ bottom of which is secured by a rubber tennis balls to preserve the buoyancy in cord around the cockpit edge and the top case of a leak or holing, and is 'provided tied snugly under the armpits of the user, with a drain plug at the Jowest point. with light braces over the shoulders. One double-bladed paddle, in two Thus, while providing protection against sections, is stowed on the decking of each spray and excluding water from the centre catamaran, and secured by rubber straps. section interior, the canopy permits the Each section may be used as a single­ occupant to leave the cockpit at will, since bladed paddle if desired, and should the the upward thrust of the body pulls the necessity arise, as a jury rudder. For rubber cord from the cockpit edge. this latter purpose a rope grummet is fitted A drain plug is fitted behind the aft on each gunwale in line with the back of eat, and a fire extinguisher on the aft the aft cockpit, to provide a fulcrum bulkhead. point for the paddle shaft. December, 1945 LIGHT MET ALS 605

ART view of Pthe two-seater power canoe with engine in position. This unit. of three horse-power, manufactured by the Norman En­ gineering Co„ Ltd., embodies light - alloy com­ ponents to the extent of 50 per cent. of its total / weight. ---- The yoke lines from the rudder are For stowage and in order to detach the carried along the centre section gunwale stern from the centre section, the yoke and provided with wooden toggles at each and rudder may be readily unshipped. cockpit position. They are kept perman­ ently in tension by rubber cords, the ends (f) Watertightness of lndividual Sections of wbich are made fast to the forward When considering the descriptions of outrigger slide. the three sections in the foregoing sub­ A waterproof cover is provided for each paragraphs (c), (d) and (e), it should cockpit, for use when the canoe is carry­ be noted that eacb is an independent ing one person only or lying at moorings. watertight section, so that if desired the To facilitate carrying and lifting, two bow and stern may be detacbed from the handles are provided on the gunwales, at centre section while afloat. each end of the centre section. (g) Power Unit lind Installation (e) Stern Section and Rudder The main specification details of the Those points already noted on the bow engine installed in the stern section have in regard to the watertight batcb, band­ already been referred to in paragrapb 3, hole and cover, apply.equally to the stern but a generał survey will furtber empba­ section, but the most notable feature is size its advantages. the propeller tunnel. This, coupled with Weigbing only 65 lb. dry, it bas already the fact that the rudder blade is hinged proven its reliability in a number of fields to the stock, enables the canoe to traverse over a considerable period. shallow"1Water and to be beached with­ Due to the horizontally opposed twin­ out difficulty or risk of damage to the cylinder four-stroke design, excellent propeller, whicb has an additional protec­ balance and mechanical silence are tion in the form of a stainless-steel skeg achieved, together with smooth running. and guard ring. The fan air cooling is efficient, main­ By means of a pulley at each end of taining the engine compartment tempera­ the yoke, the load -On each yoke line is ture at approximately 100 degrees F. halved in relation fu' the reaction on the within, of course, close limits dependent rubber blade, the miniqiur,o turning circle upon c1imatic conditions. Tbis efficiency diameter being equal roughly to twice is obtained by means of a casing which the length of the canoe. directs the air flow from the fan around 606 LIGHT METALS Decem ber, · 1945

the engine, the air intake being through water-cooled bearing of synthetic materiał two mushroom ventilators and the out­ in the outboard bracket. let through the two cowl ventilators, all Removal of the engine from the stern located on the hatch cover. The advan­ section is a simple and speedy operation. tages, due to the fact that no water pump, lt may be lifted through the hatch, after filter, water intake, outlet or pipes are­ removing the four holding-down nuts and necessary, will be readily appreciated. contact-breaker cover, and uncoupling A full pressure lubricatión system is the propeller shaft, throttle and petrol maintained at 30 lb. per square inch by connection. a duplex-type gear pump, which both Upon removal of the engine casing, feeds and scavenges, through drillings and decarbonizing is simplified by the detach­ ducts. No piping is used, thus obviating able cylinder heads; the cylinders need the risk of fracture and the resultant not be disturbed. failure of the system. The I !·galion petrol tank is slung An adjustable relief valve is included, under the decking, immediately aft of the and the filler pipe is brought to a con­ engine, an additional rubber cap, to venient position on top of the casing. ensure watertightness, being fitted over Although the engine and all working the existing filler cap where it passes parts are totally enclosed, any minor through the decking. adjustments may be made through the The engine idles at so low a speed that hatch opening. no clutch has been deemed necessary, The throttle and slow-running adjust­ the forward motion and thrust with the ment screws on the carburetter are access­ throttle closed being negligible. ible, and for cleaning the float chamber may be removed together with the jets. (h) Sailing Since the magneto is mounted on top The canoe is equipped with a simplified of the engine, the contact-breaker points lateen rig, and under sail handles· well, can be cleaned and adjusted easily. with good performance. Tappet clearances may be adjusted In conclusion, it should be pointed out after removing the casing top and va!ve that there has recently come to light a gear covers. middle-I 8th-century print of a wooden The throttle lever is mounted in a con­ boat capable of being dismantled into venient position oń the starboard side of three sections for ease of transport. the aft cockpit, and. may be quickly unclamped from its mounting when detaching the stern from the centre section. The engine switch and choke control rod are located on the stern decking. Engine starting is easy under all conditions by means of the detachable starting handle oper­ ated from the aft cockpit. The engine is mounted on 16.G. bearers and a 12.G. bed­ plate by means of four i-in. dia. bolts. The -ft-in. dia. stainless steel . propeller shaft, keyed and grub screwed into the engine coupling, Cłose-up view of the power unit. Pistons, timing­ enters the tunnel through a case cover, valve-gear covers, crankcase and Ay­ watertight gland and runs in a wheel all consist of aluminium ałloy . December, 1945 LIGHT MET ALS 607

For New Homes: WHY NOT ALUMINIUM? E. Carrington, M.Sc., presents an elementary summary of light alloys from the standpoint of the builder interested in the advantages ojfered ~Y these modern structural materials and in expediting the realizaiion of post-war planning.

VER YONE will agree that one of trial spheres. Amongst the possible uses the most important jobs to be done for aluminium alloy is the building of Ein the change over from war to houses, and when various alternative peace conditions is the prov1s1on of materials are being considered for any homes for our people. It is of the utmost part of a house, those responsible are importance that happy family life should strongly advised to ask themselves: be resumed as quickly as possible, " Why not aluminium? Is it not pos­ b·ecause on happy families is based a sible to make use of the large amount of happy nation. To this end, it is essential aluminium which is available instead of, that a reałly large number of homes or in addition to, the materials hitherto should be provided, and those who are used? " Let it be said at once that this responsible for their provision will does not mean the indiscriminate substi­ doubtless look in all possible directions tution of aluminium for other construc­ for materials which can be used for house tional or decorative materials. : Alu­ building. There are, of course, well-tried minium, like other materials, has its materials with known properties, and limitations, and every effort should be these are sure to be used on a very large made to find out whether or not the alu­ scale, although war experience may have mm1um alloy will give the service given new ideas even in the use of these expected before deciding to apply it for materials. There are also materials avail­ any new purpose. Most of the producers able which were not used for this pur­ of aluminium alloys have research pose. Amongst these are aluminium and departments, and have also a fund of its alloys- the so-called light alloys. knowledge obtained from intensive Not very many years ago, aluminium experience during the war. In addition, was practically unknown to the man in there has recently been formed the Alu­ the street, and in pre-war days it was only minium Development Associatioń. Its generally known as the materiał from purpose is to advise and assist those who which pans and kettles could be made. wish to use aluminium alloys and to take During the war the position completely every advantage of their properties. The altered, and aluminium is now known to Aluminium Development Association is a a very large proportion of our people as · very young baby, but is going to be a an important metal for the building of very virile one, and anyone who requires aircraft and aircraft engines. When used advice or assistance is strongly advised to for these purposes, it has been an consult it. The address is: Union Cham­ unqualified success, and the urgent neces­ bers, 63,. Temple Row, Birmingham, 2. sity of making the utmost use of its Phone, Midland 0847. properties and improving those properties Having seen that aluminium is not a in every possible way has provided us panacea for all ills, or a perfect substitute with a series of alloys which lend them­ for all and every other building materia!, selves to generał use in very many indus- let us try to see what it actually is. 608 LIGHT METALS December, 1945

Aluminium is a metal with a pleasing (2) " Machining of Wrought Alu­ white appearance. lt is very _light co.m­ minium Alloys," Bulletin No. 7, pub­ pared with other metals, i~s spec1fic lished by the Wrought Light Alloys gravity being 2.7 compared w1th 7.5 .for Development Association.* iron 8.9 for copper and 7.2 for zmc. (3) " Recommendations for Machin­ Con~equently, a ton of aluminium will ing Light AlJoy Castings," published by make three times as many components as Messrs. Birmingham Aluminium Cast­ a ton of copper. Against this m~s~ be ings (1903), Ltd. placed the higher price of. .alum .mrnn:i . The weldability of aluminium alloys This has recently been stab1hzed m th1s varies somewhat, but pure aluminium and country at !85 per ton. How this will most of the alloys may be welded by compare with that of other metals either the gas or arc process. An excel­ remains to be seen, but it compares very lent booklet entitled " Fusion Welding of favourably with the pre-war price of fl~O Wrought · Aluminium AJJoys" may be per ton. Most aluminium alloys contam obtained from the Wrought Light AJJoys at least 85 per cent. of aluminium and are Development Association,* the address therefore classed as light alloys. An of which is Union Chambers, 63, Temple important exception is , Row, Birmingham, 2. which contains about 10 per cent. alu­ Aluminium and aluminium alloy sheet minium and 90 per cent. copper. may be shaped by beating or spinning, Many aluminium alloys can be rolled, and guidance on these processes may be forged or extruded. Others have quite obtained from the Wrought Light Alloys good foundry properties. lt is therefore Development Association* in the form of readily seen that, whether a wrought or a an information bulletin (No. 9) entitled cast alloy is required, a suitable one can " Spinning and Panel Beating of Alu­ probably be supplied. · minium Alloys." Another method of shaping metals is An important point to consider when by machining. Aluminium alloys lend contemplating the use of metals for any themselves quite well to all kinds of purpose is corrosion resistance. In machining. Some are not so good as generał, the alloys of aluminium are rea­ others. Those containing a high propor­ sonably corrosion resistant. Pure alu­ tion of silicon drag somewhat, and the minium is quite good, and the best alloys particles of hard silicon shorten the life of are the magne ium alloys, followed by the tool. In generał , however, very high the magnesium-silicon alloys, and the sili­ speeds may be used when machining alu­ con alloys. lrmann says that while alu­ minium alloys, and sometimes the ease minium alloys are quite suitable for use and speed of machining enables an alu­ in a system using circulating water, they minium alloy casting to be produced at a do not stand up to fresh running water as lower overall cost than a similar iron well as copper alloys. When aluminium casting, although the " as cast " cost is is exposed to the air it quickly becomes higher. All tools should be given well­ coated with a very thin layer of alu­ polished cutting edges, and the teeth minium oxide, which prevents the further should be Weil spaced and the angles so attack of oxygen. Unlike the oxide of arranged that the turnings or millings are iron (rust), this layer resembles the sur­ speedily removed and do not clog the face of the metal and does not become tool. The following guides to the detached. machining of aluminium alloys will help The heat conductivity of aluminium is tho~e who may use them in our future much better than that of iron, but not so ho mes:- · good as that of copper. The relative (1) " Machining of Aluminium figures, taking silver as 100, are: <;opper Alloys, Research and Development Bulletin," published by the Northern •The Wrought Light Alloys Development Association has now been incorporated in the Aluminium Deve l op~ Aluminium Co., Ltd. ment Aasociation at the same address. December, 1945 LIGHT MET ALS 609

92, aluminium 35 and iron 16. The elec­ Under special conditions, the anodized trical conductivity figures are: silver 100, surface gives excellent reflectivity. copper 94, aluminium 57, iron 17. The Aluminium alloys may also be electro­ specific heat is 0.23 and is double that of plated. This is by no means an easy pro­ copper (0.11) or iron (0.11). In spite of cess and whatever coating is required it its comparatively good thermal conduc­ will be necessary to first deposit nickel, tivity, aluminium can be an excellent heat using one of severa! special methods, insulator. Foil is fixed on a wooden or after which any other metal which is nor­ similar support and used as part of the mally used for electro-deposition may be walls of a room. The surface of the foil deposited on the nickel. reflects the heat rays and thus prevents Aluminium alloys take a good polish. the transfer of heat through the wali. It requires some experience to obtain There are several ways of treating the identical colour on a batch of parts, but, surface. of aluminium for decorative pur­ when properly done, the effect is very poses, or to improve corrosion resistance. pleasing. lt is necessary to lacquer a A process known as the M.B.V. process polished surface in order to avoid the consists in dipping the part in a hot solu­ etfects of finger marks. tion of carbonate and sodium Aluminium itself is rather weak, its ten­ chromate for four to five minutes. A sile strength being 4 to 9 ton/ in.2 accord­ film is produced which varies in colour ing to its purity and its mechanical and from light to dark grey, with the alloy thermal treatment. On the other hand, it used. In the case of wrought alloys, the has excellent ductility and can therefore grain shows through the film , giving a be shaped easily by mechanical means. lt decorative effect. The film improves cor­ presents difficulties in the foundry, and rosion resistance but is not very resistant hence is only used for holloware and to abrasion. It is very adherent and similar castings. In the form of sheet, forms an excellent base for paint, the however, or as tubes, wire, or wrought adhesion of which it promotes. sections, it is widely used. The wrought Paint may be applied either on the sections are made by extrusion, i.e., push­ M.B.V. coating or on the metal surface ing the aluminium through a die, and a itself. Jf a little paint is removed from very wide range of sections is available. the surface of iron or steel, the rusting Messrs. British Aluminium Co., in their process spreads under the paint and " Aluminium Facts and Figures," 1938, eventually quite a large area of paint may show a good selection of these, incłuding be dislodged. This does not occur with rod, angles, channels, glazing beads, aluminium alloys. cover mouldings, handrails, gutterings, Another surface treatment which may etc. The sections regularly supplied by be applied to aluminium and its alloys is this company number nearły 4,000. They known as the anodic treatment. It is an say ("Aluminium Facts and Figures," electrical treatment carried out in either 1938, p. 79) : "The facility with which chromie, sulphuric or oxalic acid. A aluminium can be extruded is one of its strongly adherent and wear-resisting coat­ major properties. Because of this, the ing of is formed on the use of extruded aluminium sections aluminium. This may be almost trans­ instead of machined or cast components parent, or may vary in colour from dark will often show astonishing economy. grey to bronze, according to the alloy and Should any particular purpose not be met the process used. The coating is corro­ by one of the existing dies, the production sion resistant, and the corrosion resist­ of a new die is by no means an expensive ance may be increased by simple chemical matter, and would be justified when the methods. The film may also be dyed, total requirements were very small." very pleasing effects being obtained. It is Owing to the high ductility of aluminium, thus possible to produce aluminium parts extruded sections can easily be bent. which match the furnishings of the home. Sheet is supplied in severa! forms. As 610 LIGHT METALS December, 1945 a result of mechanical or thermal treat­ will help themselves by using an alloy the ment, it may be " hard," with a tensile properties of which are well known strength of more than 9 tons/ in.2, " half because of wide and intensive application hard," with a tensile strength between 7 during the war. and 8ł tons/in.2, or "soft," with a tensile A committee was formed during the strength between 5 and 6 ł tons/ in .2• The war in order to guide and advise all the surface may have a bright finish, a frosted Government departments in the use of or satin finish, or a specially polished metals. A schedule was issued, known mirror finish . If it is to be anodized, it as the S.T.A. 7 schedule, and all Govern­ should be ordered as " anodizing ment departments order metals by quality." reference to this schedule. It is hoped Fiat sheet is supplied down to 30 tbat, eventually, most private firms will S.W.G., but for gauges thinner than also do so. Group No. 6-aluminium 16 S.W.G . it is more economical to order allo ys-has recently been issued, and it the sheet in coil form. will be found to contain a wide range of There are several grades of " pure " wrought and cast alloys from which aluminium, distinguished by their degree m ate ri a ł could be selected to fulfil any of purity: 99.99 per cent. aluminium sheet purpose for which an aluminium alloy is used almost exclusively for reflectors. can be used. The S.T.A. 7 schedule is When treated by a special anodic process, avail able from the British Standards it gives really high reflectivity. Institution, 28 , Victoria Street, London, 99.8 per cent. aluminium is made into S.W. The grades of pure aluminium sheet and foil and is used where the mentioned above are included in Group highest corrosion resistance, electrical No. 6. conductivity or ductility is required. lf greater strength is required than is 99.6 per: cent. metal is similar to 99.8 obtained with pure aluminium, alu­ per cent. quality, and may be used where minium alloys are used. These may be its somewhat inferior properties are divided into two classes- wrought alloys acceptable. and cast alloys. Wrougbt alloys are so 99 per cent. aluminium is available in a called because they can be formed into variety of forms, such as sheets, tubes, shape by rolling, fo rging or extruding. holloware, panelling, food containers, Cast alloys are, of course, those which mouldings, etc. Its strength increases can be used in the foundry for the pro­ with cold work, but this increase is duction of castings. As before men­ accompanied by a drop in ductility. It tioned, the addition of alloying metals {;an be cold worked and welded. gives greater strength. The working of Before the war, there were a large these alloys by one of the above methods number of aluminium alloys avail able, gives stili greater strength, and this can and these were being added to at quite a be further improved in some cases by rapid rate. Frankly, many of these were heat treatment. Only those alloys which no better than those already in use, and contain copper and / or magnesium can be there was no so und reason for their intro­ heat treated. The fo llowing may be con­ duction. When the war carne, both in sidered to be a good all-round selection of this country and in America, the number wrought aluminium alloys : A W 2 in the .of alloys to be used was reduced to a S.T.A. 7 schedule, 9- 14 per cent. silicon . m1mmum. This simplified the supply Th is . is suitable for low- to medium­ problem and enabled scrap to be segre­ strength applications. The softer tem­ gated and remelted to produce useful pers have good ductility. lt may be alloys. lt is hoped that the number o f obtained in the form of bars and sections, alloys will remain small and that those sheet strip, tubes and wire. Jt is also who require aluminium alloys for use in avail able in the form of soft rivets and as our homes will order one of the well-tried welding rod. It is an excellent alloy for a lloys. They will help the producers and welding, and the rod is useful for welding December, 1945 LIGHT METALS 611 castings in 11 per cent. silicon alloy: 5 per are given and the alloy is said to have cent. silicon (AW 1) is another good weld­ been fully beat treated. ing alloy. A W 9 has quite a small addition of An alloy with a small amount of man­ magnesium, and when solution heat­ ganese (AW 3) may be used for similar treated is used for low-strength applica­ applications to 99 per cent. aluminium. tions. It has excellent ductility (20 per In view of its greater strength (11 to 15 cent. elongation). When fully heat treated tons/ ins.2), lighter gauges may be used it may be used for moderate strength than are called for in the case of pure applications. It is specially useful for aluminium. It may be spot or fusion thin sections, such as glazing bars, and welded. has good weldability. Severa! alloys are available containing A W 10 has medium to high strength magnesium as their chief addition, gener­ according to the beat treatment given. ally with a little manganese also. The It has good weldability. · If annealed or first of these, A W 4, is used for low- or given solution heat treatment it has very medium-strength applications. It may good forming properties and is used for be used for skins, pressings, ftoors, pipes, structural parts and mouldings. handrails , etc. The soft temper has good A W 11 , med i u :n tQ high strength ductility (18 per cent. elongation). It may according to heat treatment. It is used be spot or fusion welded. for structural mem bers, as A W 10, and A W 5 has a somewhat higher strength for mechanical parts. than A W 4, and may be used for similar AW 12, medium-strength wire and purposes. It can be spot welded and, rivets. Rivets are supplied solution beat with care, may be fusion welded. treated and are driven cold as received. A W 6 has somewhat similar proper­ A W 13, wire and rivets for high­ ties to A W 4, but is used for moderately strength application. Rivets are headed strong parts in the half-hard temper or from soft wire and must be given the after-cold working soft materiał. lt may solution treatment and driven within be spot welded and is fusion welded with 2 hrs. or else stored in a refrigerator. The difficulty. Medium-strength rivets are precipitation changes take place in this obtainable in this alloy, which are driven alloy at ordinary temperatures. cold as received. AW 14, fully heat treated forgings, suit­ A W 7 is used for high-strength appli­ able for use at elevated temperatures; cations. It is a similar alloy to A W 6. good machinability. AW 15, suitable for A W 8 is a free-cutting alloy sui table for highly stressed structures, but if corrosion use in automatic machines. lt is suitable resistance is required, only the solution for medium-strength applications. heat treatment should be given. We now come to a series of heat­ A W 16 is normall y used wbere highest treatable al!oys. The full heat treatment strength is required. It is supplied fully of aluminium alloys consists of two heat treated, and has good macbinability. processes. In the first one the alloy is AW 17 and AW 18 are suitable for heated at an accurately controlled tem­ applications requiring high strength at perature a little above 500 degrees C. and elevated temperatures. water-quenched. This is known -as the If corrosion resistance is important, the solution heat treatment. In the second alloys which are least corrosion resistant one it is heated at a lower temperature­ may be " clad "; that is, covered with a about 150 degrees C.-with similar thin coating of pure aluminium of the accurate control and eitber water­ 99.5 per cent. grade. In this way a quenched or air-cooled. This is known materia! with high strength may be given as the precipitation treatment. Sometimes a surface which is corrosion resistant. only the solution treatment is given. If In generał, wrought alloys possess maximum strength is required, with a better physical properties than cast alloys, somewhat !ower ductility, both treatments Init they are more expensive because of 612 LIGHT METALS December, 1945 the way in which they are prepared. lf when it is ready castings will be pro­ cheaper parts are required, especially if duced which will require very łittle the numbers required are small, or are machining, in the same alłoy as was used łikeły to vary, castings would be prefer­ for the sand castings. This adaptabiłity abłe. Three kinds of castings may be of aluminium alłoys could be made great obtained in aluminium alloys, nameły, use of when large numbers of parts are sand, gravity die, and pressure die cast­ required, first very quickły in small ings. lf onły a limited number of castings numbers, and łater in gradually increas­ are required they shoułd be made by ing numbers. A new process has recently means of sand moulds, because the cost beeri introduced whereby castings are of the gravity or pressure die woułd made in aluminium dies instead of iron be prohibitive. Again, if the casting dies. This process is likely to enlarge the is of complicated shape, or is very long, scope of die casting, and it appears it will be made in sand. lf large quantities probable that such things as window are required, or if dimensional accuracy frames will be cast by this method instead is 'óecessary, die castings are called for. of being built up from wrought sections, The decision as to which kind of die or cast in sand, a method which would should be used would depend upon necessitate a fair amount of after treat­ several factors. ment in order to obtain a good-looking lf there is undercut on the casting surfa ce. the pressure' process cannot be used, but In both the pressure and the gravity-die a gravity die with either a steeł core made casting process inserts of heavy metal in severa! parts, or a sand core, can be such as brass or steel are " cast in " to the employed. lf some sections are rather casting, by placing them on a secure seat­ thick the casting would not be produced ing in the die and running the metal in satisfactoriły in a pressure die. Again, if in the usual way. heat treatment is required, to give maxi­ The alloys which may be used for all inum strength, pressure die castings would three casting processes are those to Air not be chosen as they do not lend them­ Ministry specification D.T.D. 428 and D .T.D. 424, and to British Standard sełves to heat treatment. Neither are they easy to anodize. The size of the casting Specification 2L33. These are Nos. AC 1, AC 4 and AC 6, respectively, in the also controłs the choice of process, as the pressure process is only suitable for small S.T.A. 7 schedule. They are not heat treated. The first two are prepared in the castings. On the other hand, if absołute accuracy of shape is requlred, with such aluminium refinery from scrap returned from aluminium foundries and machine dimensional łimits as ± .002 in ., or if it is desired to produce small castings which shops, and are therefore comparatively require no machining, except perhaps the cheap. 2L33 must be pure, and as the reaming of a few holes, the pressure pro­ molten metal requires a special treatment cess is indicated. The process is very suit­ known as modification it is a łittle more expensive. This alloy is one of the best abłe for the production of castings with wording or diagrams cast on. Really sharp in existence for casting realły thin impressions are obtained. lt should be sections. lt has good ductiłity ; the speci­ fied figure is 5 per cent. ełongation, but pointed out that if the łetters are raised on the casting the cost of making the die 10 per cent. is generally obtained. is much less than if they are sunk. lf Another alloy produced from scrap and castings are required very quickły to given a specification during the war by enable work to be started on a few houses, Light Alloy Control is L.A.C. 112. This wooden patterns coułd first be made, is a somewhat simiłar alloy to 2L33, and perhaps of a fairly rough type, and a fair is very useful for pressure die castings. amount of machining may be necessary to It is AC 2 on the S.T.A. 7 sched ule. Light obtain the component in its fina! shape. Alloy Control developed another alloy Meanwhile, the die is being made, and known as L.A.C. 1l3A from scrap which December, l 945 LIGHT MET ALS 613 contained zinc. lt is quite a good alloy, Like the other L.A.C. alloys, it was and its comparatively high specific developed in order to use up scrap, and is gravity, due to its high zinc content, therefore a comparatively cheap alloy. lt would not be detrimental to its use in is only used for light-duty pistons. houses. It is AC 3 on the S.T.A. 7 Another piston alloy (AC 13) was sched ule. developed by the National Physical AC 5 is an excellent corrosion-resisting Laboratory during the 1914-1918 war for alloy, and might be found very useful for high-temperature use, and called Y alloy. special applications. where corrosive con­ It is often looked upon as the cast equiva­ ditions may be met with. None of the lent of the wrought alloy Duralumin. above castings are heat treated, and if There are two high-strength piston alloys cheapness were the primary consideration which a re improvements on Y alloy. when choosing an alloy, one of them These are AC l 4A and AC l 4B. They would no doubt be chosen. have a higher tensile strength and are We now come to heat-treata ble alloys. rather more castable. For generał use, there are two alloys, If an alloy is required which with­ numbered AC 7A and AC 7B. These are stands high temperatures reasonably well, grouped together beca use they have and, in addition, has a comparatively low somewhat similar compositions, different coefficient of expansion, AC 12 may be additions being made to refine the grain. found suitable. It should be noted, how­ They can both be used for sand or ever, that this alloy has the worst gravity die casting. machining properties of all the alu­ If high strength is required, especially minium alloys, and requires considerable if some ductility is also needed, high­ care a nd experience if a first-class surface purity alloys a re used which require close finish is to be obtained. technical control a nd great ca re in casting No doubt many of those who contem­ and heat treatment. Two alloys of this plate using aluminium or its alloys in the type are the magnesium, corrosion-resist­ construction or decoration of our homes ing alloy AC 9, and the copper-containing would Iike further details of the alloys alloy which is numbered AC lOA, if given given a bove, and might also like to know a single heat treatment, and AC JOB , if if there a re alloys which would be given a double heat treatment. These specially suitable for some new or alłoys are by no means easy to use in the unusual application. Full details as to sand foundry, and in the gravity die shop specified composition and physical pro­ a re only used fo r castings of small size or perties, and the heat treatment required, if simple shape. Nevertheless, a very large any, are given in the relevant Air Minis­ tonnage of both sand and die castings has try (D.T.D.) or British Standard (B.S.S.) been cast during the war fo r aircraft Specification. The available equivalents parts. If somewhat lower tensile and to S.T.A. 7 alloys a re as follow:- elongation figures are acceptable, and Aluminium Equivalent especially if the casting is difficult to cast, A 4 99 per cent. aluminium AC 8 could be used. This is simila r to ingot B.S.S. 2L3 I AC 6 and has excellent casting properties 99 per cent. wrought for either są nd or die castings. · bars and sections, as extruded . . B.S.S. L34 There is a type of alloy which, after 99 per cent. tubes, being heat treated, may be used at fa irly t hard B.S.S. 4T9 high temperatures (say, 300 degrees C.), 99 per cent. sheet and without losing the benefit of heat treat­ strip, soft . . B.S.S. 2lJ 7 ment. These a re classed as the piston 99 per cent. sheet and strip, ł ha rd . . B.S.S. 2LJ6 alloys, but they may, of course, be used 99 per cent. sheet and for other purposes. One of these alloys strip, hard . . B.S.S. 2L4 was developed by Light Alloy Control 99 per cent. wire and and was labelled L.A.C. 10 (AC 11). rivets . . B.S.S. L36 614 LIGHT METALS December, 1945

Wrought Alloys Equivalent Casting AUoys Equivalent A W 3 Sheet and strip, ł hard D.T.D. 653 AC7 Sand and gravity die, A D.T.D. 133C Sand and gravity die, 8 Sheet and strip, ł hard D .T.D. 213A D.T.D. 287 A W 4 8ars and sections, as AC8 Sand and gravity die, extruded B.S.S. L44 artificially aged, A . . D.T.D. 240 Sand and gravity Tubes, soft D.T.D. 3108 die, fully H.T., 8 D.T.D. 245 Tubes, t hard D.T.D. 440 AC9 Sand and gravity die, Sheet and strip, soft . . D.T.D. 634 solution H .T. o :T .D . 300 Sheet and strip, t hard D.T.D . 606 AC 10 Sand and gravity die, D.T.D. 1808 A W 5 Sheet and strip, soft. . A, solution H.T. .. D.T.D. 198 A W 6 Wire, welding rod and Sand and gravity die, rivets, soft .. D.T .D . 303 8, fully H.T . . D.T.D . 304 A W 7 8ars and sections, soft D.T.D. 297 AC Il Sand and gravity die, Tubes, soft D.T .D . 190 fully H.T. L.A.C. 10 Sheet and strip, soft. . D.T.D. 182A AC 13 Sand and gravity die, A W 8 8 ars for machining fully H .T . .. 8.S.S. L35 (free cutting) 8.S.S. 1080 AC 14 Sand and gravity die, A W 11 8ars and sections, A, fully H.T. D.T.D. 1318 solution H.T. D.T.D. 443 Sand and gravity die, 8ars and sections, 8 , fully H.T. D.T.D . 255 fully H.T... D.T.D. 423A A W 12 Wire and rivets, solu­ D.T.D. specifications may be obtained tion H .T . D.T.D. 327 from H .M. Stationery Office, York AW13 Wire and rivets, solu- House, Kingsway, London, W.C.2. tion H .T. 8.S.S. 2L37 AW 14 Forgings, fully H .T ... D.T.D . 130A B.S.S. specifications may be obtained D.T.D. 410 from the British Standards Institute, 28 , AWl5 8ars, sections and Victoria Street, London, S.W.1. forgings, solution Any further inquiries regarding either H.T. B.S.S. 6Ll wrought or cast alloys should be sent to B.S.S. 2L39 the Aluminium Development Association Fully H.T. D.T.D. 364A at the address already given. Tubes, solution H.T ... 8.S.S. 5T4 Fully H .T. D .T .D . 464 In addition to joining aluminium alloy Sheet and strip, solu- parts together by welding or riveting, it tion H.T. D.T .D . 603 may be found desirable to fix aluminium 8.S.S. 5L3 parts to wood or similar materi a ł. lf Sheet and strip, fully steel screws are used, there is always a H .T . D.T.D. 646 danger of electrolytic corrosion, due to Aluminium - coated sheet and strip, solu- the setting up of a galvanic cell when two tion H .T. D.T.D. 390 unlike metals are in contact, especially if D.T .D. 610 they become wet. In order to avoid this Aluminium - co a t e d trouble, aluminium screws may be used. sheet, fully H.T. D.T.D. 546 They are available with raised, round or AW16 8ars and sections, fully H.T. D.T.D. 363A countersunk heads, and the sizes are AW17 Forgings and stamp- given in the British Aluminium Co.'s ings, fully H .T . 8.S.S. 4L25 " Aluminium Facts and Figures," 1938, AWl8 Forgings and stamp- pp. 74-75. ings, fully H.T. B.S.S. 2L42 It is hoped that the above account has Casting Alloys shown that aluminium and aluminium alloys are exceedingly useful from both AC I Sand and gravity die .. D.T.D. 428 the constructional and decorative points AC 2 Pressure die L.A.C. 112 of view, for the construction and im­ AC 3 Sand L.A.C. 113A AC 4 Sand, gravity and pres- provement of our homes. When con­ sure .. D .T .D. 165 sidering, then, the varrous alternatives AC 5 Sand and gravity die .. D .T.D. 424 which can be used for the rapid construc­ AC 6 Sand, gravity and pres- tion of a large number of houses-why sure .. B.S.S. 2L33 not aluminium? December, 1945 LIGHT MET ALS 615 New Low-priced Car 1n Aluminium

The People's Car of France, Designed by ]. A. Grćgoire and Referred to and Described on Marry Previous Occasions in "Light Metals," will Soon be Seen on Roads in Great Britain. Manufacturing Rights Jor the British Empire Jor this Model Have Been Acquired by a British Group . . T is known that CoL Devereux recently remarkably low petrol consumption of 71 made a flying visit to Paris to secure miles per galion at 30 miles per hour, and I the manufacturing rights of the car 58 miles per galion at 60 miles per hour. designed by J. A Gregoire which the The gearbox is of four-speed, overdrive

LLUSTRATED at the I left is a view of the chassis and scuttle as­ sembly of the Gregoire car. All the significant elements here are in light alloy. Reproduced below is an illustration showing further struc­ tural details.

French Government has chosen to manufacture as the " National Car." This car embraces many novel features, the chief of which is that the main structural members are made up of alu­ mm1um castings, a feature which offers great economies in production costs. This four-seater, front­ wheel-drive car weighing only 800 lb., is powered by an air-cooled 549 c.c. engine which gives the 616 LIGHT METALS Decem ber, 1945

ROUP ot components all in alu­ G minium alloys which are amongst those which go to make up the Gregoire car. Aluminium-alloy castings form the bulk of the assembly. ty pe. There is independent suspension oi1 all wheels. lt is anticipated that this car will be sold at a price considerably below any so far available in Great Britain. Manufacture in this country, in con­ junction with tractors and other cars, will Jt is anticipated that the advantages be undertaken by W. D. Kendall, M.P„ derived from the extensive use of light of Grantham Productions Ltd„ who alloys in this car will create a wicie hopes to maintain an output of 500 cars interest in the form of construction per week. employed and that it will be incorporated This ·new car has been so designed as in other manufacturers' designs. to take full advantage of the remarkable For the manufacture of the aluminium­ combination of lightness and strength alloy castings, which fulfil the most offered by modern aluminium alloys, and important functions in this car, the great of · the highly developed production resources of Renfrew Foundries Ltd„ techniques which have been evolved dur­ owned jointly by Almin Ltd„ and Rolls­ ing the war. Royce Ltd„ will be available. December, 1945 LIGHT METALS 617 __ General, Techni~al NEWS and Commercial

A Novel Refrigerator Car corrosion and to transmit the heat evol11ed NOTHER instructive application of to water. Originally, armour vests during Aaluminium all oys to transportation is the war were made from manga nese steel, noted in the Aluminum News Letter­ but it was found that aluminium a lloys were October, 1945. lllinois Central Ra i! Road resistant to small shell fragments. These have, in the design stage, a novel refrigerator protective vests, made of aluminium, nylon car to be constructed from aluminium alloys, and canvas, weighed only 44 oz. per sq. ft. and which, by the use of collapsible bulk­ of protection, 38 per cent. less than the heads, can be transformed to a box car in earlier airman's ferrous armour.\ The a few minutes. The van will weigh about insecticide D.D.T. and pyrethrum were used 14,000 lb. less than the refrigerator car in in a solution of Freon contained under use at present. pressure in a container consisting of an Co-operating to perfect the design were aluminium tip and syphon assembly. the United States Fruit and Vegetable Air Pressure Tight Castings Associati on, Car Const ruction Committees of the Association of American Railroads, LLUSTRATED in the latest News­ and the Al!-lminum Company of America. I letter is another novel use of gravity die castings. Wagner Electric Corporation, St. Aluminium-" Now lt Can Be Told " Louis, Mo., are producing a transportable ONTAINED in Alcoa's News-Letter for hi gh-press ure air contai ner for the servicing COctober, 1945, are stories of the part of motorcar hydraulic brake systems. al uminium pl ayed in the atom bomb, in The container assembly is approximately body armour for warplane crews, and in spherical in shape, but the interesting D.D.T. mosquito fighting equipment. feature is that two hemispheres are produced Uranium slugs were "canned " in alu­ by permanent mould methods and then minium sheaths to protect them from welded together.

Announcing Formation of Almin, Ltd. JN conjunction wi th Lazard Brothers and and Almin, Ltd., in order to acquire and Co., Ltd., and Erlangers, Ltd., Col. W. C. operate commercially the largest and best Devereux, F.R.Ae.S., has incorporated equipped light-alloy foundry in Europe at Almin, Ltd. (i.e.. Associated Light Meta l Hillington. near Glasgow; Warwick Aviation, lndustries), in order to implement his pl ans Ltd., which will continue to be managed by for the scientific development and extended its founder, M r. L. E. Metcalfe, as a fabri­ application of li ght metals and their all oys. cating unit and manufacturer of finished The new company, of which Col. Devereux articles; a forging and extrusion unit, now is managing director. has a capital of being formed; and as the life centre of the U ,000,000, and the ot her directors are Mr. group, a research in stitute devoted to the P. Horsfall as chairman, Mr. Leo d'Erlanger metallurgy of the light alloys and kindred and Mr. Spence Sanders. Throug)\ sub­ studies for the service not only of the Almin sidiary or associated companies it wi ll group but of anyone who wishes to avail co-ordinate the financial and commercial himself of its resources. policy of a group of undertakings, extending The operating companies, associates with from sc ientific research and engineering Almin, Ltd., already employ more than 5,000 development and design through all stages people and there is every reason to believe from the refining of the metals and all oys that the group will before long provide to the production of finished light-metal employment, directly or indirectly, for many goods. These undertakings include .Inter­ more in a branch of industry in which this national Alloys. Ltd .. which with its sub­ country possesses knowledge and s kilł unsur­ sidiary, Light Alloys Products Co. (Birming­ passed anywhere in the world. ham), Ltd., is the largest British producer of It is not the intention for the time being high q.uality li ght-all oy ingot; Renfrew to make an offer to the public of shares in Foundnes, Ltd .. which has been established, Almin, Ltd., or its associated companies, or a nd is owned jointly by Rolls-Royce, Ltd., to seek a Stock Exchange quotation. 618 LIGHT METALS December, 1945

Aluminium-magnesium System had already drafted regulations for admis­ HE !atest addition to the Institute of sion by examination and otherwise to three TMetals Annotated Equilibriurn Diagram grades, Fellows, Associates and Licentiates. Series is that of the alurniniurn-magnesium " It is the intention," said Dr. Moore, " that system. By G. V. Raynor, M.A., O .Phil. the Institution, by setting high standards of (Institute of Metals Annotated Equilibrium competence, shall serve the public interest Diagram Series No. 5. 11 ! ins. by 8-f ins. and make an important contribution to Pp. 6 with I fig. 1945, London: The Insti­ industrial efficiency. Possession of the Insti­ tute of Metals, 4, Grosvenor Gardens, tution's qualifications will be evidence of S.W.1. 6d. post free.) It contains (a) the capacity to undertake responsible work as diagram reproduced on a generous scale and a metallurgist. " At the meeting, high based on what is regarded as the most officers of kindred institutions voiced a warm reliable work in each phase field ; (b) a table welcome to the new organization. giving all important data connected with the di agram; (c) a number of critical notes; and R.-R. Foundry, Hilłington (d) a list of reference. H E Roll s- Royce aluminium foundry at Nos. I to 4 of the series are stili available, T their H illington, Glasgow, factory is price 6d. each post free. They deal respec­ to be continued into peace-time production tively with the. aluminium-zinc, copper-tin, under a new arrangement between Colonel copper-zinc and copper-aluminium systems. W. C. Devereux, F.R.Ae.S., and Rolls­ R oyce, Ltd., and the Ministry of Aircraft Death of G. J. Edwards Production. . E \:egret to announce the death, on The . range of projected mass-produced WNovember 3, of Mr. G. J. Edwards, goods includes office and domestic furniture. Chairman and Managing Director of Edgar cookin g and kitchen equipment and utensil s, Vaughan and Co., Ltd., Legge Street, Bir­ domestic equipment of every typ\!, and an mingham, in his 64th year. equally wide range of products in the indus· Mr. Edwards was well known and highl y trial sphere, for the shipbuilding, aircraft. respected fn the oil industry and engineering vehicle and transport industries as well as for trade, with which he had been associated for industry in general. The greater part of the the past 36 years. output will be aimed at the export market. Planned in 1938 and brought into produc· Instifution of Metallurgists tion in June, 1940, the foundries reached T a widely representative meeting in their maximum output of aircraft engine ALondon on November 28, it was castings in 1943, when an aggregate output announced that a professional institution of 7,800 tons was achieved. for metallurgists had been formed. Dr. Harold Moore, C.B.E., the President, who for many Aluminium Houses by Blackburn years was director of metallurgical research HE first aluminium houses at Dumbar­ at the Armament Research Depa rtment, T ton have now been erected by Blackburn Woolwich, and later director of resea rch for Aircraft, Ltd., Dumba rton , whose yard. the British Non-ferrous Metals Research throughout the war, turned out Sunderland Association, said that while metallurgy was fl yin g-boats and other types of aircraft. This one of the oldest of the a rts, it was one of change-over was achieved only six days after t he youngest of the sciences. Metallurgists the last of the 250 fl yi ng-boats made by the were well served with learned and technical factory had been launched. C. A. Oakley, societies, but there was no organizati on that regiońal controller Ministry of Aircraft Pro­ could represent their common interests, duction, stressed, however, that the yard was express their corporate views, or give the essentiall y one for the production of air­ hallmark of a recognized professional qualifi­ craft and that it was essential that that cation in metallurgy. For a long time there should not be ignored. When flying-boats had been a widespread desire for a new were again in demand, he hoped to see the organization admitting only qualified metal­ Blackburn yard produci ng them. lurgists and having functions supplementary Major F. A. Bumpus, managin g director to, but independent of, those of the existing of Blackburn Aircraft, Ltd„ also pointed out metallurgical institutes and societies. that the factory was a peace-time planned The Institution of Metallurgists had, unit and not a war-time development. He therefore, been incorporated with the active would be glad, he said, to see a return to help of the Iron and Steel Institute and the the production of aircraft as soon as Institute of Metals. The provisional council possible. December, 1945 LIGHT METALS 619

''Aluminium-War to Peace "

EFT:-Milking pail L and containerforliąuid chemicals by F. Brahy and Co., Ltd., Bristol. Bath items are of large capacity and their construction in light-metal results in a wel­ come reduction in dead­ weight.

ELOW : - Panel of B special hammers by "Thor," Birmingham. Thesetoolshave light-alloy heads on wooden shafts and are more comfortable to use than copper hammers and, for some purposes, may even replace the raw­ hide type.

HE centenary year of aluminium is T drawing to a close. It has been a period not without its progressive changes. Long experience and intensive scientific research within many factories, finds the light-metal industry again ready to play an essential part in the national peace-time campaign for export and overseas markets. Within a few weeks of the German capitulation, the aluminium industry opened in the heart of London a show which, throughout the month of June, attracted some 8,000 visitors a day. That first demonstration aroused not only the interest of metallurgists from all parts of the world, but evoked the praise and admiration of artists, designers and craftsmen alike with a display of industrial skill which has set new standards in exhibition technique. Even Selfridge's, that house in Oxford Street famous for its triumphs of pre­ sentation, declared the aluminium ex­ hibition to be one of the most successful they had ever staged for the benefit of a critical British public. Thousands of sight-seers at that first showing in London saw the true signifi- 620 LIGHT MET ALS December, 1945 cance of it all, and realized that a milestone vincial cities, and, infallibly, the same deep in progress had indeed been reached-the impression has been created. Aluminium Age, a promise of events which Jn Birmingham, where the attendance was bid fair to lighten and brighten a war-weary even greater !han London, was found an world. insatiable demand for booklets, pamphlets­ Tnspiration was evident at the very any kind of literature which prov,ded details entrance to the exhibition, in that array of of the exhibits. On show there were two new exhibits worthy of mention-a greenhouse with detachable glazing bars in aluminium · alloy by the Patent Glazing Co., Ltd., of Birmingham, and a sailing canoe by Warwick Aircraft. Co., Warwick, together with a 3 h.p. outboard motor by the Norman Engineering Co. The new greenhouse demonstrated admirably the advantages of aluminium-alloy glazing bars, showing not only a saving of weight and a greater lighting area, but also a detachability which most gardeners greatly desire. Aluminium glazing bars have been in use for more than 14 years, and in this country have competed very successfully with those of other metals. The effect of weathering on many installations has been recently investigated, and in all cases the findings were satisfactory. At Hammersmith Hospital, London, for example, the glazing bars-although they have been in position for nine years with no protective coating- are stili in excellent condition. From Birmingham, the exhibition was transferred to

BOVE :- Section of A "są uare " corrugated heavy-gauge aluminium sheet by Steel Fabricators Ltd., Bir­ mingham. IGHT :-Roof section ex­ R hibit by Austin Aero Co., show design and method of fixing the special light-metal­ sheet tiles manufactured by this company.

murals brilliantly conceived by Ralph Lavers Bristol, where, at the Bristol Museum, on to show the various processes by which alu­ November 5, it was officially opened by minium is produced and fabricated. Those Professor Andrew Robertson. President of who saw the screen representing the "Fore­ the Institution of Mechanical Engineers. word" to the story of aluminium- a mural Professor Robertson drew attention to the with metallic lettering which stood out like great quantities of light metal which were polished silver on a black-dye anodized now available and emphasized the need for ground surrounded with motifs to indicate engineers and constructors to examine the " Genesis," " Stone Age," " Bronze Age." possibilities offered by light metals. He and ·' Iron Age "- understood how cleverly briefty outlined the history of aluminium and the artist had depicted the steps by which the referred in particular to the resistan:e it present Age of Aluminium has evolved. This offers to those corrosive inftuences respon­ hall of murals has accompanied the alu­ sible for the annual losses of such great minium exhibition on its tour of the pro- quantities of structural steel work. Decem ber, 194 5 LIGHT METALS 621

To the already growing list of items which cannot be o btained with paper. Par­ shown in Birmingham, three new exhibits ticularly striking, for example, is the fact were to be seen in Bristol; the mgst attrac­ that, viewed from a very oblique angle, the tive of these were, undoubtedly, examples of subject and colours can stili be seen. colour printing by the " Decora! " process of From the design point of view it might be E. S. and A. Robinson. This system involves interesting, too, to comment on the system the use of an anodized aluminium sheet into of framing adopted for the Robinson panels. The pictures were mounted on the front of wooden blocks, the moulded ed&es of which retreated from the picture. This is possible with alu­ minium, as the surface needs no protective glass covering and, furthermore, is, in itself. sufficiently bold to endure the prominence inio wh:ch it is thrown. Attention was drawn in a past issue of " Light Metals" to special hammers with light­ alloy heads; those illustrated at the time were of German origin. Similar items made in

OLO frame fitted with C special li g ht-ałloy detach­ able glazing bars as iłlustrated at the right and below.

IGHT : - End view of R patent glazing b3r, show­ ing stop. Below: - Patent glazing bar, showing open end.

France were · shown at the recent Pa ris Fair, and, at Bristol, was exhibited a panel of such hammers by - " Thor " of Birmingham. Steel Fabricators, Ltd„ of Birmingham, showed a series of massive corrugated alu­ minium panels, whilst the Austin Aero Co. provided a roofing assembly cover with specially designed a lu­ minium tiles. F . Braby and the treated surface of which colours a re Co., Ltd., of Bristol, placed on view a new a bsorbed to produce, fundamentally, the milking pai!, together with a light-metal same ultimate effect as in three-colour pro­ receptacle for chemicals. Amongst the cess work, with these differences, however, smaller, exhibits was a model demonstrating that the texture of the metal exerts a pro­ a new draught excluder designed to fit any found effect on the fin a ł result obtained and door and fabricated from light-metal adds to the colours a " life and warmth " section. 622 LIGHT METALS December, 1945 Light Metals zn the FOOD AND ALLIED INDUSTRIES Presenting the First Part of an Exhaustive Survey of the Theory and Practice of the Use of Aluminium and Aluminium Alloys in the Industrial and Domestic Processing and Handling of Foodstujfs

LUMINIUM is no newcomer to those coming into service in the food and related industries specializing in the prepara­ industries. The main apprehensions of the A tion of goods intended for human would-be user of aluminium appear to be consumption or which, because they come connected with questions of the durability into contact with the human skin or with and efficiency of aluminium plant, the possi­ the inside of the human mouth, require bility of the light metal exerting any detri­ especial care in all stages of processing and mental effect on the foodstuffs and other dispensing to guarantee their purity and to products with which it comes into contact, ensure that their and the question of nutritional or thera­ cost. There are, peutic value is main­ therefore, two factors tained. Even more to be considered, widespread is ·the namely, the reasons use of aluminium, why light metals mainly as plain or come into the picture decorated foil, in the at all and to what packaging and dis­ extent they c a n play of these goods. satisfy· these three Light metal also crucial points. figures in the trans­ Dealing first with port of the finished the ultra-light alloys goods and, some­ because there is less times, of the raw to say about them, materials, too, so the magnesium-base that it can be said Fig. 1.-Frying pan for contact heating cast alloys ha ve only a in pure magnesium. This has been in con­ without exaggeration tinua! use since July, 1945, over an open gas very limited applica­ that aluminium has flamę ; no distortion of the bottom has tion at the present rather a universal occurred. After use it has been regularly time in the fields a p p e a 1 in all cleaned with steel wool and soap flakes under consideration. branches of such together with washing soda; it stili remains Whilst their resis­ industries as the bright and shows no sign of corrosion tance to attack by dairy, beer, wine, although, after standing idle for a few days, certain media is tobacco, confection­ it does acquire an easily removable not­ highly specific, their ery, cosmetics, phar­ unpleasant-looking whitish film (Courtesy reactivity generally maceutical a n d Dominion Magnesium Co. Ltd.) is too great to allow similar industries. of their use in con­ In many of these applications, aluminium tact with more than a very small proportion has become the recognized materia! to use; of the raw materials and finished products in other applications, and even in cases and their use is confined rather to applica­ where the advantages of aluminium are tions in which the utmost reduction in weight quite indisputable, .progress has been slow. is required in parts not exposed to any con­ Often this has been due simply to lack of siderable corrosion hazard. At the moment it knowledge concerning the light metal and, is probably unwise to formulate any hard as its characteristics become better known, and fast statements in this regard, however. a great advance is being made in this clirec­ With aluminium, however, the position tion and more and more light metal is is very different. Not only is it numbered December, 1945 LIGHT MET ALS 623 among the few materials wh ich can be rancidity when they are packed. in foils of employed safely in contact with foodstuffs, other metals. but it also combines valuable structural Aluminium is resistant to many oxidizing characteristics with simple methods of agents; in fact, the presence of oxidizing fabrication at a cost which is seidom exces­ agents frequently lessens the attack by corro­ sive. For packaging and 'display purposes, sive materials. Thus, increased resistance to the availability of aluminium in the form chloride impurities in tap water is obtained of foil is very advantageous. in the presence of a little soluble chromale As stated above, inadequate appreciation or dichromate. of these factors and lack of knowledge of Ammonia gas and ammonia solutions have the properties of aluminium and its light very little effect on a luminium, but strong alloys have contributed largely to the slow alkilis, and particularly the caustiĆ alkalis, rate at which aluminization is being adopted dissolve the metal and must not be allowed in certain branches of industry, and it is to come into contact with it. A number of largely in an endeavour to alter this state milder alkalis such as sodium metasilicate, of affairs that the present article is written. sodium carbonate (soda ash), sodium bicar­ The plan of this contribution is, first, to bonate, trisodium phosphate and soft soap examine briefly the generał c; l}aracteristics of also tend to attack aluminium slowly and the light aUoys with emphasis on those pro­ their use in cleaning solutions is best avoided perties which make these metals of interest except in the presence of a suitable inhibitor. to the food industry and, secondly, to deal Useful inhibitors, are, fortunately, quite in greater detail with realized, and a few commonplace materials and sodium silicate potential, applications in specific fields. in amount about IO per cent. of the alkali metal salt or about I per cent. of a soluble Corrosion Resistance chromate or dichromate are generally One of the greatest difficulties which beset employed. For application in the food the chemical engineer and food packer alike industry, chromates and dichromates are best is the selection of m a teriał which is least avoided because of the possible harmful affected by, and which itself has the least effects of any retained chromium compound effect on, the materials and atmospheres on the human system and the choice falls with which it comes into contact. Under naturally on to sodium silicate. Thus, solu­ normal conditions, the stability of aluminium tions containing 0.5 -5 per cent. soda asJ:i and is high and it shows very good corrosion 0.05-1 per cent. sodium silicate are efficient resistance in comparison with most other cleansing materials, for example, in the dairy common metals. Thus, on norma! outdoor industry, and yet, at the same time, cause exposure, aluminium surfaces seidom suffer no appreciable attack on the aluminium. greater damage than the formation of a thin Some proprietary cleansers for aluminium film of tarnish provided they are washed incorporate inhibited sodium metasilicate. down once or twice a year to remove corro­ lt must never be forgotten, however, that the sion nuclei which, if undisturbed, are liable addition of silicate does not prevent corro­ to develop into pits. sion by caustic alkalis, and under ńo cir­ lt is resistant to sulphur and many sulphur cumstances can these materials be used for compounds in marked contrast to the yellow cleaning aluminium. lt is believed that sili­ metals and, indeed, to most ferrous metals, cate functions as an inhibitor by virtue of and it can be relied upon to give good the deposition of colloidal silica gel, and service in sulphurous atmospheres or in con­ it is a fact that corrosion in the food indus­ tact with sulphur-containing materia ls where try is often reduced or even prevented the ferrous and yellow metals would be altogether by the fortunate presence of liable to attack leading to rapid breakdown sugars and various colloidal materials essen­ of the metal component and to contamina­ tial to the various food preparation ti on of the product. Sulphur dioxide rarely processes. has more than an insignificant action on Hypochlorite sterilizing solutions can be aluminium whilst, even with sulphuric acid, used on aluminium, although there is a the rate of attack is sufficiently low to enable slight attack. A solution of I oz. of chlor­ the metal to give good service in many amine T per IO gallons of water is also applications in industry where metal pans, used because its rate of attack is very much etc., come into intermittent contact with )ower. this acid. This is important since many As far as brines are concerned, aluminium foodstuffs contain traces of acids or sulphur is seriously attacked by alkaline brines, but compounds which give rise to bl ackening or much less so by neutral solutions; in the 624 LIGHT METALS December, 1945

latter case, attack may be almost entirely carbons have no action on aluminium and inhibited by the addition of a small amount the metal possesses satisfactory resistance (0.17 per cent.) of sodium chromale. Some towards other substances which are fou[d of the special refrigerants such as freon in small amounts as impurities in hydr·'­ (dichloro-difluoro-methane) have no action carbons and hydrocarbon products (St ·. upon aluminium and aluminium-magnesium phurous materials, for instance), or wh;. alloys. are used in admixture with them to sec1 The behaviour of aluminium in contact certain desirable properties. with solutions of the salts of the heavy Generally speak ing, alcohols are withou· metals depends on the difference of potentia! effect on aluminium, but the influence c between it and the metal ion in question. small amounts of impurjties may, on ra r Frequently this difference is considerable occasions, be very marked. and the aluminium is attacked. Thus, in Ethers uncontaminated by acids are with­ the case of copper salts, copp.er is deposited out action on aluminium, whilst amines, Iii·„ from the aqueous solutions on to the ammonia solutions, may give ri se to a s li~ " aluminium and a corrosive couple is formed initial attack as a result of which ' which results in rapid and severe pitting of adhesive and rather impermeable layer vi the aluminium. It is, therefore, important corrosion product is soon formed on the to guard against the formation of electro­ metal surface and which prevents further lytic couples in aluminium plant since it is attack unless it is destroyed by, for example, nearly always the aluminium that suffers; an inorganic base or a halogen salt. zinc is an exception and has been made use The fatty acids vary quite widety in their of in a few instances in the chemical effect on aluminium, but, in generał , attacl\ engineering field to provide protection to the is negligible at norma! temperatures. Gro~ ­ aluminium at . the expense of zinc sheets quantities of impurities may accelerat located nearby. Aluminium in juxtaposition attack and not infrequently corrosion b· to brass, for example, should be insulated · dilute solutions is greater than with concen from it in some way or another; for in stance, trated solutions. Nevertheless, aluminiu1 by the use of a gasket or by means of shellac must be classed as one of the most safo paint. Similarly, cooling brines should not factory metals to use in contact with fatty be allowed to come into contact with acids and, in point of fact, it is already used copper, brass and other heavy metals during extensively in industries treating fatty acids their circulation through the pl ant. Other­ at norma! temperatures in the construction wise traces of yellow metal are dissolved of storage tanks and so on. The use of and, later on, are thrown out of solution aluminium equipment prevents that darken­ on to the aluminium, where they give rise ing and discoloration of the product S(' to loca! galvanic attack on the light metal. inse parable from the use of other met a l ~ This question of bimetallic corrosion need such as iron and copper. not deter would-be users of aluminium equip­ Considerable aluminium equipment is in ment, however. The phenomenon is well use in the .handling and transport of acetic under!Kood and its solution seidom involves anhydride, glacial acetic acid and acetic acid more than the insertion of a few gaskets solutions, as well as for the higher homo· and the elimination of yellow metal from logues of acetic acid. The higher fatty ac id ~ liquid circulation systems. Attention to these (oleic, margaric, palmitic, stearic, etc.) arc details is, however, vitally necessary to the generally quite inert to aluminium even afte· successful working of aluminium plant and prolonged contact at the boiling point pro equipment. vided they are not completely water-free. Aluminium is scarcely attacked by dry Formie acid is the only real exception. This steam and only slightly by wet steam, but m ate ri a ł attacks aluminium fairly readily high pressure steam is likely · to erode the and no adequate protection is available. metal, particularly when the jet is perpen­ Ethyl, butyl and amyl acetale and other dicular to the metal surface. The severity of esters of the fatty acids which are employed erosion depends upon the velocity and tem­ in industry as fruit essences, perfumes. perature of the steam and on the hardness solvents and intermediate products have no of the alloy. Attack by water depends upon effect on aluminium. Since, moreover, the the impurities it contains, but is usually very metal is not attacked by small amounts of small. retained acetic and sulphuric acid s which Even more marked is the resistance of are employed in the esterification proces!', aluminium towards organie materials. aluminium is revealed as a most suitabk Thus, saturated and un saturated hydro- metal to employ in the handling, processing December, 1945 LIGHT METALS 625

and transport of these materials since it taric, citric and malic acids, since these a introduces no contamination to impair the present in many food products, fruit juice odour, taste or colour of the product. sour milk, and so on. These acids and the Alumfoium equipment has given consider­ solutions have only a slight attack able satisfaction in contact with formalde­ aluminium at norma! temperatures. Th hyde. Not only is it practically unaffected a ttack, which is largely independent of co by the aldehyde, but, in addition, it does centration, increases with rise in temperatu not accelerate decomposition of this rather and becomes much more pronounced unstabli.: substance, a behaviour which is in 60 to 70 degrees C. It can, however, near marked contrast to a lmost every other metal. always be reduced to negligible proportio Care sl10uld be taken, however, to ensure by the presence of colloids or fats whi that thi.: aldehyde is free from formie acid. act as inhibitors; milk, for instance, has le The halogen compounds of the hydro­ effect on aluminium than an aqueous sol carbons (ethyl chloride, ethylene chloride, tion containing only lactic acid in the sa dichlorethylene, trichlorethylene, perchlor­ concentration as it was contained in the mil ethylene, chloroform, carbon tetrachloride, In consequence, in applying data relati ethylene bromide, etc.), a nd such materials to the effect on a luminium of pure aqueo as iodoform, have no action on a luminium solutions, it must be remembered that t at normal temperatures when dry. Should action of the fruit juice or other produ any decomposition occur, however, the of complex constitution may be ve corresponding halogen acid is formed and different from that of the dibasic or hydro the metal is lia ble t() severe corrosion. acids it contains. Aluminium equipment h The halogen acids, and the ha logens, too, given satisfaction in the processing of frui for that matter, a ll attack a luminium a nd fruit juices and is being used to strongly, a lthough the high purity metal does increasing extent for their packaging. exhibit some resistance to dilute solutions, Similarly, albumen and gelatine are wit even of hydrochloric acid. In some cases, out action on aluminium and equipment however, the effect of these acids can be this metal has given every satisfaction in t largely inhibited, certain resins a nd a ryl production of gelatine for human consum sulphides being effective in this respect. tion. Whilst glucose (grape sugar) and pu· Thus, the effeet of hydrochloric acid on lactose (milk sugar) are without action a luminium is largely inhibited by the addi­ aluminium, light metal is unsuited to t tion of quinoline or benzyl sulphide and production of the latter since the crude mi suc.h inhibited acid has been recommended sugar contains acids which attack the met for cleaning equipment free from beer scale, The action of glues on aluminium depen milk stone and boiler scale. The advantage on their pH and their compositio of this materia! over the nitric acid which Usually, neutral glues are without action is more commonly employed appears to lie aluminium, although alkaline or acid glu in its more rapid action, together with its may cause some pitting. In view of t freedom from the evolution of noxious la rge demand for such prnducts as pape brown nitric fumes. In addition to such backed aluminium foil , special adhesiv isolated and specia lized applications as this, have been developed and these have giv information on the effect of such potent every satisfaction. There is, in fact, reagents as the halogens and halogen acids special difficulty in the adhesion is relevant since these materials, in small aluminium beyond that of narrowing do amount, may come into contact with the the field of available adhesives and selecti light metal through slight decomposition of one with sufficient adhesive power in vie other products or through the retention of of the smooth nature of aluminium f these substances from earlier prosessing. surface and one which does not contain Whilst the vulnerability of aluminium to corrosive constituent. The fact that th such corrosive substances as the halogen creates no special difficulty is exemplified acids and caustic alkalis is admittedly a the quantity of backed foil which has be great drawback, it must not be forgotten used satisfactorily to

N "Light Metals," 1939 I 2 I 11 was noted a new chassis frame, amongst other a remarkable vehicle of light-alloy con­ things. In this case, however, the side struction built by Jensen. Motors, Ltd .. members were straightened and the E West Bromwicb. About that time, diagonals re-riveted, since which repair >ur of these vehicles were completed : the vehicle has been in regular use with 1ey differed in various respects but all entire satisfaction. nbodied the same principles. Through­ Apart from such a special case as that, ut the war they have been in constant it is instructive to lea rn that every rivet >e and have covered many thousands of in those four vehicles has held tight, and tiles apiece, without suffering any there has been no sign of corrosion. oubles due to the materials used or the Using the experieące gained with the 1ethods of construction. _ early models, together with the lessons One was involved in a serious accident, learat in war-time fabrication of a variety !ing hit broadside on with such force of products, this same company has now ,at it was turned on its side, and its load designed and built the JNSN lightweight as thrown over a hedge. This eau ed commercial Yehicle which combines the image which with many conventional same basie light-alloy construction with !signs would probably have necessitated carefully selected mechanical com-

HIS three-quarter front view of the new JNSN gives a good idea of the size of the cab in T which, incidentally, same cadmium-plated steel tubing is employed. Decembe r, 1945 LIGHT METALS Advts. xxv FROM WARPAINT TO FINE FINISHES

Wherever the weapons and instruments of war have needed the utmost surface protection, the finish specified has been Cellon, Cerrix, Cerrux-or a blend of the special ingredients upon which the supreme quality of these tough finishes ,je pen ds.

Beauty has not been part of our war time duty. The high grade raw materials always used in Cellon products have necessarily been reserved for use wherever human life or the efficiency of our arms have depended upon preservation from the elements--including tropical beat, arctic cold and the insidious attack of sea-water. Now that these materials are once more becoming available they will be placed, as rapidly as possible, at the disposal of industry. Meanwhile, excellent substitutes for many purposes can be supplied at once. Consult us for

help with y our prohlem.

CELLULOSE SYNTHETIC

CELLON LTD., KINGSTON-ON-THAMES TELEPHONE: KINGSTON 1234 (5 LINES) Thorp„Hambrock. Co. Ltd., Montreal, Canoda Cellon Corporatlon Pty. Ltd., Sydney, Australia 628 LIGHT METALS Decem ber, 1945

EASURING 23 ft. M by 7 ft „ the łoad­ ing area of the new JNSN is believed to be the largest avail­ able on any make of 4-wheeler. The two­ part drop sides close on to a detachable centre post. Renew­ able timber inserts give long life to the corrugated aluminium- alłoy floor.

ponents by specialist manufacturers. tion placed at suitable points, which The vehicle is well able to take advantage include the spring anchorages. Diagonal of its lega! maximum speed of 30 m.p.h., braces, also of light alloy, are disposed due to an unladen weight of less than 3 along the length of the frame to increase tons, although it can carry loads up to lateral rigidity and to prevent any 6 tons. " lozenging." All the joints in this main While on the subject of carrying capa­ structure are riveted. city, it may be noted that the loading Carried directly on the main beams, area of the body is no less than 16 I są. the floor consists of light-alloy sheet ft. ; the length and width are 23 ft. and formed into rectangular corrugations. 7 ft. respectively. With little doubt, this The spaces on the upper side of the floor must make it the largest platform on four are filled with timber strips which stand wheels under the regulations in this proud of the metal and take all the wear. country. The corresponding overall In this way strength and lightness are dimensions of the complete vehicle are combined with long life. Even when the 27 ft. 6 ins. and 7 ft. 6 ins. wood has worn down, it can easily be The body and the chassis together replaced without great expense. form, in effect, a unit. Two straight and Drop-sides and end are fitted, the side deep I-section light-alloy beams extend panels being in two lengths for ease of from end to end of the vehicle, being operation, and the centre posts are joined by cross-members of similar sec- quickly removable, so that they need not xxvi Advts. LIGHT METALS Decem ber, 1945 The better use of

Where to look for further economies

YO U MA y HA VE DECIDED that you have reached the limit of improvement in efficiency of power usage. But are you sure? Why not make doubly sure by going through these Bulletins point by point,? If your search reveals only a single possibility it will have been well worth while. The probability is that you will find many. Tum up these Bulletins: FUEL ECONOMY BY SAVING ELECTRICITY FUEL ECONOM Y AT COLLIERIES (Bulleti11 No. 13) (Bulletin No. 32) A rapid survey of the possibilities. The colliery officia! will find this Brief, practical pointers that take · Bulletin a real boon. lt is a guide you straight to sources of sub­ to the economical operation of stantial · economy in electricity colliery compressed air plant, but consumption. it also contains a brief sum mary of hints on steam boilers, prime THE INDUSTRIAL USE OF COMPRESSED movers, fans, pumps and so on. AIR (Bulleti11 No. 29) Compressed air is a very con­ SMALL VERTICAL BOILERS , STEAM CRAl~ES venient medium of power trans­ AND SHUNTING ENGINES mission. But it can also be a great ( 8111/etin No. 37) waster of power unless carefully These power units are often supervised and maintained. This neglected. How fuel losses can be Bulletin tells you what to look for reduced and operation improved and how to pul it ri ght. is explained in a very practical way.

UNTIL YOU HA VE looked into the possibilities of every recommendation in these Bulletins you ought not to decide that your power is being used efficiently. lf you haven't all the Bulletins ready at hand , please ask for the copies you need from the Regional Office of the Ministry of Fuel and Power. A ~ 1SSUED BY THE MINISTRY OF FUEL AND POWER December, 1945 LIGHT METALS 629

ESIDES the unusu Bradiator gń lle lormir the name Jl\SN, t standard eąuii:ment the new vehic le includ two driving mirrors, log and pass lcmp, a a near-side lamp proje ing a long, fiat tcp bea in lieu of dipping. T width of the cab especially to be noted.

interfere with the loading of lengthy his seat are the clearly marked containers articles. The hinges for the sides and end for the brake fluid, the Kigass paraffin have integral hooks for roping on a load (for cold startiag), and the chassis lubri­ or attaching a tarpaulin. cating oil, which is distributed by a By removal of the ends and sides, this Tecalemit unit operated by the clutch body is converted, at once, into a fiat pedal and embodying a separate small platform, and later there will be other pump for each point requiring lubrica­ body types, ir.cludiag a van. tion. In this way every such point is In the cab there is some steel framing, served without interference by what may square tubes being used for certain parts be taken or refused by other parts. to give the desired rigidity. The doors, Returning to the cab, the fuse box is for instance, have frames of this kind. accessibly placed and the battery is These, and all other steel parts of the mounted behind the mate's seat, which, frame and body, are cadmium plated to by the release of a large knurled-headed prevent rust or corrosion. Although it setscrew, can be tilted forward so as to occupies only 4 ft. of the vehicle Jength facilitate inspection or topping-up. (there being the usual small gap at the Ventilation of the cab has not been front of the body) the cab is not at all overlooked. Apart from the fact that the cramped. lnside each front door pillar driver's side of the windscreen can be there is a hand-rai! which makes entry opened, there are two adjustable venti­ very easy. The driver's seat is adjustable lators in the front of the cab. In cold vertically as well as horizontally. There weather, these can be closed and warm is exceptionally good visibility and all air admitted ·through two ventilators in the controls are quite handy. the bonnet. There is also a ventilator in Just behind the driver on each side of the roof. 630 LIGHT METALS Decem ber, 1945

Cerium 1n Light-alloy Technology Marked Improvements in Mechanical Properties may be Obtained by Regulated Additions of this Metal

NVESTIGATION into German war-time fo r pistons when creep and fatigue at ele­ I metallurgical practices, with special refer­ v a te~ ser:'ice temperatures are important ence to ordnance, aircraft, and the like, has cons1derat10ns34• Support to this is given by revealed the extensive use of cerium as an the Battelle Institute's investigati ons on alloying element or as an additional agent in enemy ordnance7, by Sutton's findin gs on light alloys. ' Non-ferrous Metals in Enemy Aircraft ,"B Cerium is always associated with its sister and by Goddard's " Outlook for Magne­ elements, but, fortunately, these exhibit sium. "9 Sutton's findings coincide with the closely similar properties, and it is not report by Murphy3·1 on li ght-metal all oys usually necessary, therefore, to isolate pure conta ining cerium. Latest British all oy speci­ cerium metal. " Misch metal " is the name fi cations35 mention fi ve cerium alloys. Car­ given to the metal mixture, the composition rington36 names cerium-aluminium alloys as of which varies somewhat according to the the most useful and preferable in his li ght­ origin of the raw materia! from which pro­ metal .alloy classification for foundries. duced. The American cenum standard a1l oy The Battelle report on enemy ordnance falls approximately in the following range:- - mentions an a ll oy of 93 .0 per cent. magne­ Cerium 45 to 50 per cent. sium, 5.5 per cimt. cerium, and 1.5 per cent. Lanthanum 22 to 25 per cent. manganese, which is used in a front cam fol­ Neodymium 15 to 17 per cent. lower guide in a BMWD-2 engin e of a Praseodymium 8 to 10 per cent. Focke-Wulf 190 German aircraft. The prime Terbium .. . reason for the use of this a ll oy was high­ temperature stability. Yttrium .. . l O to 5 per cent. lllium Another alloy comprised 93.7 per cent. Samarium .. f magnesium, 1.45 per cent. manga nese, 0.03 Iron ... O.I per cent. per cent. sil icon, and 4.55 per cent. cerium, Silicon 0.3 per cent. and this was used in a supercharger impeller This is the type of materia! generally used, on a German .aircraft engine BMW SOJ A: and research indicates that the results, usiri g ease of forging is given as the reason for this technically pure cerium, a re the same with choice. respect to micro-structure, physical, and The 5. 5 per cent. cerium alloy had a hard­ chemical properties. ness value of 80 Bri.nell at room temperature the first reference to cerium in metal alloy­ and 45 at 400 degrees F. ing was in 190437, when it was added to BecklO states that the German a ll oy aluminium under a protective flux of AM537 contains 0.5 per cent. cerium, has a chlorides of sodium and , and, density of 1.769 and the highest thermal con­ fundamentall y, this procedure is probably ductivity of all magnesium alloys, and that it stili the same to-day. G. Ahrens, of the is markedly superior to the same all oy with­ Cerium Metals Corporati on, N ew York, out the cerium addition. Greater fluidity of under the heading of " New Uses for the all oyed magnesium in foundry practice is Cerium," gives the following informati on one of its reported attributes. upon important alloys of cerium with both Beck gives micrographs which indicate aluminium and magnesium in " Metals and marked grain refinement in magnesium-man­ Alloys," September, 1945, from which the ganese all oys by the addition of cerium. bibliography included herein is also taken. Tmprovements are also noted in the follow­ Generally, tests indicate an improvement in g properties:-Modulus of el asticity, notch­ in the micro-structure of castings from impact, 'shear, deep drawing properties, wear­ secondary aluminium when cerium is a ócled. in g qualities, fatigue, and creep. Heat treatment of cerium..containing alu­ The Battelle Institute report adds confirma­ miniurp alloys is stated to give improved ten­ ti on to Beck's deductions, and commends the sile strength, elongation, and hardness. sound and perfect German castings as repre­ Cerium-aluminium alloys are recommended senting the highest state of the aluminium December, 1945 LIGHT METALS 631 founders' art. Freedom from cracking in a strength, grea ter elongation, augmented hard­ very complicated casting, evident easy cast­ ness, improved creep resistance, better fatigue ability, good properties in the actual casting, and thermal resistance, facilitated castability. freedom from porosity, shrinks, and other less liability to cracking, and superior ther­ foundry troubles; these are quoted as a tri­ mal properties. bute to the alloy and technique acquired. Although cerium is not always found in REFERENCES analysis, its presen·ce is inferred. Borcher'sl2 patent refers to the properties obtainable (1) "Metal lnduslry,'' March 30, 1945 ; from the use of cerium in aluminium refin­ "Modern Metals," May, 1945 ; by S. Smirnow­ Verin, Novosli Tek.hnik.ie. (2) Borchers and ing before casting, although analysis of the Stok.em, German Patent No. 172,529; Muthmann, completed alloy showed no trace of cerium. "Anna/es," 1902, 231,320; 1904, 1,331; 1907, The effect of cerium was well defined, and 116,355. (3) Juk.kola, Audrielh; B. S. Hopkins, SchuJtel3 confirms Borcher·s work. Again. "]. Am. Chem. Soc.," Vol. 56. 1934, p. 303. Smimow-Verin1 found 16.6 per cent. rejec­ (4) Thrombe," Trans. E/ectrochem. Soc.,'' Vol. 66, tions in aluminium-alloy piston castings, 1934, p. 231. (5) Hirsch, " Chem. Met. 67 per cent. for cracking. 33 per cent. for Engineering," Vol. 9, 1911, p. 940. (6) "Z.f. porosity. By the addition of 0.35 per cent. angew, Chemie," Vol. 28, Part I, pp. 319-328. cerium to the alloy, rejections for these faults (7) "Metal Progress," Battelle Institute, February, were completely eliminated. 1945. (8) H. Sutton, "Metal lnduslry," Apri/ Houghton and Schofieldl4 also report 28, 1944, and May 12, 1944. (9) G. Goddard, upon the beneficial effects from cerium addi­ "Metal lnduslry," Seplember, 1944. (10) Beck., "Technology of Magnesium," 1940 lranslationfrom tions to light alloys, and advocate a special Beck., 1939, Germany. (11) Grain slruclures, melting technique to achieve the best results. Microphotographs from Beck.'s book.. (12) Borchers, Biltz and Pieper20, in their paper on alloying German Patent No. 246,484. (13) Schulte, practice, give further evidence that cerium "Metali und Erz," XVIII (N.F. IX), Vol. IO, in aluminium-magnesium alloys is beneficial 1921. (14) ]. H. Houghton, T. H. Scho/ield, "]. for grain refining and scavenging effects, and Insi. Metals," Vol. 60, 1937. (15) U.S. Patent add support to the belief that the excellenc.: No. 1,915,932, Magn. Deve/opmenl Corp. (16) of the German castings depends in part upon Barth," Metallurgie," Vol. 9, p. 261. (17) Th. cerium additions to the melt. Goldschmidt, Essen, British Patent No. 266,696. The National Smelting Co.23 employs (18) "Brass World," March , 1920. (19) Rolla, cerium as an optional addition to heat-resist­ Jandellie, Caneri, Vogel, "Z. f. Metallk.unde," ing, low expandable aluminium alloys. February, 1943. (20) Biltz and Pieper, "Z. /. 1 anorg. Chemie," 1924, p. 234. (21) Heraeus Rolls-Royce2 similarly regards it favourably Vacuum Schmelze, German Patenls Nos. 631,985, in high heat applications for internal-com­ 740,480, and U.S. Patent No. 2, 144,200. (22) bustion engines. /. G. Farbenindustrie, U.S. Patent No. 1,818,556; :Wellinger and Keil25 compare the German "Amer. Foundryman's Assn„" 1921, p. 626. alloy "Mahle 549," which is a magnesium­ (23) National Smelting Co„ Canadian Patenls Nos. cerium-manganese alloy, with 14 other high­ 424, 133, 424,415. (24) Rolls-Royce, F rench strength aluminium alloys. This cerium Patenls - Nos. 797,714, 819,263. (25) Wel/inger alloy possesses better creep resistance. and Kei/," Z. f. Metallk.unde," Vol. 35, Seplember, Desch26 also shows thai cerium-magnesium 1943. (26) C. H. Desch, Nat. Phys. Lab„ Royal alloys have strength characteristics akin to Aeron. Soc„ 614th Lecture, 1937. (27) Anton those of the Y alloys. Kratk.ey, Australian Patent No. 123,225, Swiss Patent No. 136,096. (28) Le Magnesium Indus­ Kratky27 shows improved corrosion resist­ trie/ de Paris, U.S. faleni No. 1,816,983. (29) ance in magnesium-cerium-aluminium alloys. I. G. Farbenindustrie, French Patent No. 624,449; The Magnesium Development Corporation15 British Patent No. 263,755. (30) Ullmann, and the Societe Le Magnesium Industrie! de "Encyclopredia,'' Vol. 2, Part III, 1939, p. 181. Paris28 show improvement in the forging pro­ (31) "Metals and Al/oys," F ebruary, 1945. (32) perties of light alloys from the addition of Cata/ogue of Cerium Metals Corp. (33) Muthmann, cerium. l.G.Farbenindustrie use cerium in "Anna/es," Vol. 46, 1904, p. 331. (34) piston alloys. and Specialloid, Ltd.37, find "Metallurgia,'' January, 1945, A. ]. Murphy; cerium additions improve heat resistance "Modern Metals," ]une, 1945. (35) Brit. Light and diminish thermal expansivity. Alloys Spec., "Light Metals," December, 1944. (36) "Light Metals," March, 1945, Carrington, From these references. the evidence indi­ S Joundry al/oy classi/icalions. (37) "Automobile cates that additions of cerium from 0.2 per Eng.,'' October, 1944, December, 1944; "Light cent. to 0.5 per cent. to aluminium and to Metal Age," March, 1945; "Modern Metals," rnagnesium alloys result in specific benefits, May, 1945 ; British Patenls Nos. 556,224, viz„ improved grain structure. higher tensile 557,070, 558,562. 632 LIGHT MET ALS Decem ber, 1945 LIGHT-ALLOY AUTOMOBILES Comments by M. Boghossian, of L'Aluminium Francais, on an Account Which Appeared in "Light Metals," 1.945 /8/417

HE article given in " Light Metals," · reduced by about 40 or 50 per cent. without T September 1945, aroused consider­ going to the extreme of using three wheels. able interest in France, but due, poss1bly, in the case of the Mathis a very rvuch greater to difficulties of communication, certain reduction has been achieved. It is, in fact, corrections are necessary regarding the calculated that the drag coefficient of the specification and performance of the Mathis Mathis is only 27! per cent. as great as for car. In the fiest place, the capacity of the the more conventionally designed Panhard engine is not 530 c.c. as stated, but 700 c.c„ of Gregoire. This reduction of nearly 75 per the stroke and bore figures being 75 by cent. has enabled Andreau to achieve a speed 80 mm„ and although the power output of increase of some IO m.p.h. with a very low 15 b.h.p. is correct, it is achieved at output. 2,500 r.p.m. and a piston speed of 2,670 ft. As mentioned before, the consumption per minute and not 3,000 r.p.m. with a fi gures for this car are almost unbelievably piston speed of 2,370 ft. per minute as low-95 m.p.g. at 41 m.p.h. average point­ stated in " Light Metals." Moreover, side to-point speed and 114 m.p.g. at a steady valves are used, not inclined overhead valves, sustained speed of 44 m.p.h. These fi gures and the transmission is through conventional alone are ample justification for the recourse Spicer joints and not trac,or joints. by M. Andreau to a three-wheeler layout, The maximum speed of this car is and to obtain stability with this arrange­ 63 m.p.h„ and the fuel consumption realized ment a special study had to be made of is the remarkable figure of 95 m.p.g„ and on springing and weight distribution. It would the Gregoire-Panhard the corrected fi gures certainly be difficult to reduce consumption are 55 m.p.h. and 68 m.p.g. to the above figures with the conventional On the subject of how far reduction in four-wheel type, and it is certain that it weight is affected by the mass of light alloys would be impos.si ble to do so without goi ng introduced, it is our experience that one to the very maximum of weight reduction should not seek to deduce any general law and drag reduction. The results given by in this matter. However, we believe that it this small car are, however, such that it is possible to take a vehicle with an initial becomes easily poss ible to imagine four­ weight of 3,300 lb. and to reduce the weight wheeled cars of greater capacity, larger by over 1,500 lb. by introducing only 550 lb. overall size, more comfortable and with of light alloys. better performance than those now pro­ The important relationship between weight duced. We consider that it will be possible reduction and drag reduction was particu­ to produce a comfortable five-seater weighing larly realized by Andreau when he decided less than 12 cwt. empty, havin g a drag to adopt three-wheeler layout for the Mathis. coefficient about 60 per cent. lower than con­ Although it may be true, as Pomeroy ventional practice and a fuel consumption of remarks, that the aerodynamic factor can be 44! m.p.g. at 50 m.p.h.

OBJECT LESSON ! E recently received the following letter twisted piece of metal o e 9yards a way. Wfrom the Technical Editor of "The " Once upon a time, however, it had been Motor ":- rather above the ordinary run and had had " For the past ten days I have been stay­ a cabriolet type body with li ght alloy frame­ ing in one of the few undamaged buildings work for the folding top. The body panels in Wiesbaden and have looked out over a themselves were of steel and where the square containing on one side the remains cellulose had been toro away the ~ were of the Rathaus and the windowless but rapidly rusting. The chromium plate on the relat:vely undama.ged cathedral. On a lamps and windscreen was peeling off, broad piece of pavement on the other side leaving horrible orange scabs, but, shining of the square was the remains of a like a light in darkness, were the stili highly Wanderer car, a product of the Auto Union polished light-metal sections of the body; Co. Of this particular specimen nothing they appeared literally· as new and provided much was left; the wheels and tyres had a remarkable, because entirely accidental, been taken, the engine lifted out, the proof of the corrosion-resisting properties of front seats had gone, thę bonnet was a i::o rrectly selected light alloys."-L.P.