(12) United States Patent (10) Patent No.: US 6,857,558 B2 Ferry, III Et Al

USOO6857558B2 (12) United States Patent (10) Patent No.: US 6,857,558 B2 Ferry, III et al. (45) Date of Patent: Feb. 22, 2005

(54) METAL LAMINATION METHOD AND 4,399.611 A * 8/1983 Maringer ...... 30/350 STRUCTURE 4,816,347 A * 3/1989 Rosenthal et al...... 428/615 4.881,430 A 11/1989 Hubbard ...... 76/104.1 (76) Inventors: Robert Thomas Ferry, III, 16005 SE. 5,226,578 A * 7/1993 Douglas ...... 228/157 5,253.796 A * 10/1993 Stacher et al...... 228/193 322ND St., Auburn, WA (US) 98092; 5,410,133 A 4/1995 Matsen et al...... 219/645 William Cottrell, 8914 Colony La. SE., 5,425,494. A * 6/1995 Rosenthal et al...... 228/124.5 Tenino, WA (US) 98.589; Charles 5,532,460 A 7/1996 Okato et al...... 219/621 Bybee, 22964 NE. 26th Pl, 5,579,988 A * 12/1996 Schutz et al...... 228/235.2

Sammamish, WA (US) 98.074 5,797.239 A 8/1998 Zaccone et al...... 521/793.1 5,815,790 A * 9/1998 Billgren et al...... 41.9/5 (*) Notice: Subject to any disclaimer, the term of this 6,564,689 B1 * 5/2003 Billgren ...... 89/16 patent is extended or adjusted under 35 2003/0119599 A1 * 6/2003 Byrne et al...... 473/340 U.S.C. 154(b) by 0 days. FOREIGN PATENT DOCUMENTS (21) Appl. No.: 10/375,525 EP O908263 4/1999 JP 56-9085 * 1/1981 (22) Filed: Feb. 26, 2003 JP 56009085 1/1981 JP O9-283812 * 10/1997 (65) Prior Publication Data JP 11-043760 * 2/1999 US 2003/0162050 A1 Aug. 28, 2003 JP 2002-OOO971 * 1/2002 OTHER PUBLICATIONS Related U.S. Application Data (60) Provisional application No. 60/361,070, filed on Feb. 27, U.S. Appl. No. 60/343.865.* 2002. * cited by examiner (51) Int. Cl." ...... B23K20/04; B23K 20/14; B32B 15/01; B32B 3/26 Primary Examiner John J. Zimmerman (52) U.S. Cl...... 228/190; 228/219; 228/235.2; (74) Attorney, Agent, or Firm-Seed IP Law Group PLLC 228/262.71; 428/635; 428/660; 428/614; (57) ABSTRACT 428/609 A method of forge welding laminates of titanium and (58) Field of Search ...... 428/635, 660, titanium alloys includes interleaving first and Second plu 428/614, 609, 612; 228/190, 218, 221, ralities of metal pieces in an enclosure, filling the enclosure 220, 235.2, 219, 262.71 with an inert gas, heating the enclosure and the first and (56) References Cited Second pluralities of metal pieces, and mechanically preSS ing the enclosure on a first axis with a force Sufficient to U.S. PATENT DOCUMENTS cause the first and Second pluralities of metal pieces to 3,201.863 A 8/1965 Sayre ...... 29/472.3 forge-weld together. The first and Second pluralities of metal 3,748,721. A 7/1973 Alexander ...... 228/185 pieces may be metallurgically dissimilar from each other, 3,963,589 A * 6/1976 Kushida et al...... 205/206 and may each comprise a percentage of titanium. 4,137,616 A * 2/1979 Veitlet al...... 29/17.3 4,354,301 A 10/1982 Takeuchi et al...... 29/160.6 34 Claims, 11 Drawing Sheets

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B4 86 | WZZ 80 Fig. 14C US 6,857,558 B2 1 2 METAL LAMINATION METHOD AND materials. This means that these components or materials are STRUCTURE prone to corrosion and can add Significant weight to the final product. Forge welding of other metals has been attempted, CROSS-REFERENCE TO RELATED without good results. For example, efforts to achieve a APPLICATION reliable forge welded laminate of titanium or titanium alloys This application claims the benefit of U.S. Provisional has been generally unsuccessful. Patent Application No. 60/361,070 filed Feb. 27, 2002, In an attempt to forge-weld other Steel alloy materials, where this provisional application is incorporated herein by different techniques have been attempted. See, for example, reference in its entirety. U.S. Pat. No. 5,815,790. This patent describes a technique in which two Stainless Steel materials, at least one of which is BACKGROUND OF THE INVENTION in powder form, are placed under isostatic pressure while 1. Field of the Invention being heated to a high temperature. Working with metals in This invention is in the field of metal laminates, and more powdered form is difficult and expensive. particularly relates to metal laminate Structures of Hot isostatic compaction, or hot isostatic pressing (HIP) nonferrous, noncorrosive metals. 15 is known in the industry, and used, for example, to form 2. Description of the Related Art parts from metallic powders, including powders of Steel, A number of conventional techniques exist for the bond aluminum, and titanium. HIP requires a cylindrical pressure ing of metals to achieve composite or laminate products. vessel into which the material to be processed is inserted. One technique is forge welding, which is used for the The interior of the vessel (and the material) is heated to a manufacturing of compound Steel, wherein two types of high temperature, and the atmosphere of the vessel is Steel are bonded together in open atmosphere to produce a preSSurized to pressures Sufficient to compact a powdered composite product. In order to achieve Such a composite, metal into a solid form. The HIP process requires expensive plates or layers of Steel are heated to a high temperature and machinery and has limits to the size of the parts that can be pressed together, using a pressure Sufficient to cause the made thereby, Since a pressure vessel capable of withstand plates to form a molecular bond. One of the advantages of 25 ing huge pressures is required for the process. The vessel forge-welding over other methods of joining metals is that must be internally insulated from the heat of the process, to the bond is achieved without the use of additional metal. prevent the extreme temperatures from weakening the walls This may be contrasted with arc welding, for example, of the vessel under pressure. AS the size of the vessel where an electrode of a metal that is compatible with the increases in a linear manner, the required thickness and metals to be joined is heated by the passage of an electric Strength of the vessel walls increases exponentially. This current, to melt and become part of the welded joint. This places a practical limit on the maximum size of parts that can alters the chemical makeup of the metal at the joint. Physical be produced. Currently, the maximum working Size is on the characteristics, as well as the appearance of the joined parts order of around four feet in diameter. It will be recognized are changed. While this may be desirable in Some cases, in that, as the size increases, the cost of owning and operating others it is not acceptable. A properly forge-welded joint is 35 Such a device also increases. Additionally, the materials in a extremely strong while retaining all the physical character preSSure vessel cannot be handled or manipulated in any istics of the component parts, as well as presenting an way until the procedure is complete. These issue, individu ally or in combination, make the use of HIP expensive and attractive (sometimes invisible) bond. complicated for Small parts, and impossible for large ones. This type of forge-welding has been practiced for many 40 years and is also known in the industry as pattern welding. BRIEF SUMMARY OF THE INVENTION Another common term for this technique is damascened According to one embodiment of the invention, a method forging, with Steel made by this technique being referred to is provided, comprising the Steps of arranging first and as Damascus Steel. Knife blades made from Damascus Steel Second metal pieces in an enclosure, filling the enclosure have been used for many years and are valued for the 45 with an inert gas, heating the enclosure and the first and decorative and artistic qualities, as well as for the high Second pieces of metal, and mechanically pressing the quality of the blade. enclosure on a first axis with a force Sufficient to cause the One of the benefits of Damascus or forge welded steel is first and Second pieces of metal to forge-weld together. The that a blade made using this technique tends to enjoy the first metal piece may be one of a first plurality of metal advantages of each of the component ingredients. For 50 pieces and the Second metal piece may be one of a Second example, a Steel alloy having a high degree of flexibility may plurality of metal pieces, with the arranging Step comprising be combined in alternating layers with an alloy having interleaving the first and Second pluralities of metal pieces Superior hardness. The result is a blade of great flexibility with each other. The first and Second metal pieces, or the first that also takes and holds a Sharp edge. It is not fully and Second pluralities of metal pieces may be metallurgi understood how characteristics of individual alloys are 55 cally dissimilar from each other. Additionally, each of the imparted to Such a composite, when a Single alloy composed first and Second metal pieces, or each of the first and Second of the Same ingredients and in the same proportions as the pluralities of metal pieces may comprise a percentage of combination of the two component alloys does not, titanium. generally, capture the combination of characteristics. Another embodiment of the invention provides a metal Nevertheless, the phenomenon has been known and 60 laminate, including a first plurality of layers of a first metal exploited by master Smiths for centuries. containing titanium, a Second plurality of layers of a Second Regrettably, the techniques used to make Damascus Steel metal containing titanium, the Second metal having a chemi are only effective on a very limited group of Steel products. cal composition different from a chemical composition of Only those steels that have a very high workability and low the first metal, with the first and second pluralities of layers alloy content are able to be worked with this process. 65 interleaved with each other, and with each of the layers of Currently the knife-making industry is limited to unal the laminate having a forge welded bond with the layers loyed or alloyed carbon Steels for decorative composite contiguous thereto. US 6,857,558 B2 3 4 BRIEF DESCRIPTION OF THE SEVERAL gases to escape under exhaust and the rear cap 18 has a VIEWS OF THE DRAWINGS larger aperture for input of gases in order to fill the chamber with the appropriate gas content during the treatment. The FIG. 1 includes a modified, exploded of an encapsulating Small hole in the front cap may be in the range of around chamber. /s-1% inch in diameter and the rear hole in the range of 2-1 FIG. 2 is an isometric view of various alloys placed within inch in diameter in one acceptable embodiment. the encapsulating chamber. A handle 22 is connected to the chamber 10, as shown in FIG. 3 is a side elevational view of the encapsulating FIGS. 2 and 3, preferably by connecting to the rear cap 18, chamber having an inert gas flow therein in preparation for by any appropriate mechanism. In one embodiment, the treatment. handle 22 is a metal pipe that is welded over the rear hole 19, which provides the dual purpose of Serving as a handle FIG. 4A illustrates one embodiment for placing the encap for carrying the chamber as well as an inlet pipe for gas to Sulation chamber under high pressure. be pumped into the chamber at a later Stage in the process. FIG. 4B illustrates a second embodiment for placing the encapsulation chamber under high pressure. In carrying out the invention, the rear cap 18 is connected 15 to the chamber 10 and the handle 22 is then connected to the FIG. 5A is a side elevational view of the encapsulation rear cap 18, as seen, for example, in FIG. 3. The chamber is chamber being placed under high pressure. now prepared to receive the metal to be laminated into a FIG. 5B is a side elevational view of the encapsulation Single thick Stock. Thin plates 24, 26 of Selected alloys are chamber rotated 90 and placed under high pressure. stacked into the chamber 10. The plates 24, 26 stacked into FIG. 6 is an isometric view of the final billet of laminate the chamber 10 are of an acceptable size and shape to fit material. Snugly into the chamber and to have a Sufficient number FIG. 7 is an isometric view of the elongated billet. within the stack for the desired number in the final laminate. FIG. 8 is a side elevational view of an artistic pattern According to one embodiment, the materials used are tita being pressed into the billet. nium alloys of various materials and compositions. One of 25 the layerS may be a commercial grade pure titanium. One FIG. 9 is a side elevational view of the billet being acceptable grade is known in the industry as CP grade 1 machined to a desired shape and having a desired artistic titanium. This is a lighter colored metal 24 as indicated in pattern. FIG. 2. In between the generally pure titanium layer 24, an FIG. 10 illustrates, in plan view, a simple design pressed alloy layer 26 of titanium is placed. This alloy can be any into a portion of the surface of the billet. acceptable alloy of titanium that is compatible with being FIG. 11 is a cross-section of the portion of the billet of bonded to the pure titanium in the process. One example FIG 10. includes an alloy known as titanium 6AL4V, meaning 6% FIG. 12 is a plan view of the portion of the billet of FIG. aluminum and 4% vanadium with the remainder being 10, showing the appearance of the billet after the upper titanium. Other acceptable alloys of titanium include tita Surface has been removed. 35 nium alloy 13AL3Z; titanium 13AL3V, titanium alloy 6AL, 3CR; and various combinations of titanium alloy with FIG. 13 is a cross-section of the billet of FIG. 12. aluminum, Vanadium, chromium, nickel, Zinc, and other FIGS. 14A, 14B and 14C illustrate some possible arrange metals. Alternatively, another alloy is used in place of the ments of parts in the chamber of FIG. 1. pure titanium, Such that two different alloys are bonded. In 40 a further embodiment of the invention, more than two DETAILED DESCRIPTION OF THE different metals are placed together in the chamber 10 to be INVENTION bonded. AS is illustrated in FIG. 1, an encapsulating chamber or According to an embodiment of the invention, the sheets enclosure 10 is provided, which initially is open at both of titanium and titanium alloy may be Scrubbed and cleaned, ends. The chamber 10 can be made of a mild steel box tube, 45 if desired, to remove all Surface oxide layers and impurities, or Steel Square or rectangular tubing of another type of metal prior to loading them into the chamber 10. The scrubbing as Starting member. The chamber 10 has any desired height, can take any acceptable form, Such as a mechanical Scrub, a width, and length. According to one embodiment, the width wash, or a chemical bath. The scrub is selected to be w is in the range of 1-2 inches, the height h is in the range Sufficient to remove any oxide layers, nitride layers, or any of 2–4 inches, and the length 1 in the range of 4-10 inches. 50 other build-up of materials caused by dirt or by a reaction In one preferred embodiment, the rectangular tubing to form with the atmosphere, the result of which is to expose the pure the chamber 10 has a width won the inside of 1% inches and metal. After being appropriately cleaned and Scrubbed, the /s inch thick walls for an overall outside width w of 1/2 metal plates 24, 26 are placed into the chamber 10 in inches. The inside height is 3 inches and the length is 6 preparation for the bonding process. After the metal is inches. 55 placed in the chamber 10, the front cap 12 is bonded to the Such material may be easily obtained from commercial chamber 10 by any acceptable technique. metal supply companies. The chamber 10 has a front end 14, As shown in FIG. 3, an inert gas 38 is then pumped in at a rear end 20, sides 32, 34, a top surface 28 and a bottom a Selected rate Sufficient to displace all nitrogen and oxygen Surface 30. A front cap 12 is connected by any acceptable in the chamber 10. The inert gas is preferably pumped in at technique, Such as welding, adhesive, Strapping, or other 60 a slow rate So as to evacuate all atmosphere and leave only attachment method to the front end 14. A rear cap 18 is pure inert gas within the chamber 10. Pumping at a Slow rate coupled to the rear end 20 of the chamber 10 by any ensures that pure inert gas will be present rather than a acceptable technique, Such as welding, brazing, adhesive, mixture of inert gas and ambient air, which contains Some Strapping, or other known method. The front cap 12 and rear oxygen and Some nitrogen. A preferred inert gas is argon, cap 18 have appropriate apertures 13 and 19, respectively, to 65 although other gases besides argon may be used. At this permit Selected gases to enter and exit. In one preferred point in the process, the hole 13 may be plugged by any embodiment, the front cap 12 has a Small aperture to permit appropriate method. Alternatively, the hole 13 may be left US 6,857,558 B2 S 6 open, in which case the inert gas may be pumped at a very constant pressure of the hydraulic press, additional heat is low rate into the chamber 10 during the next steps of the generated in the center of the Stack. The force that com process, to prevent recontamination of the atmosphere in the presses the top 28 and bottom 30 closer to each other by chamber. Some distance will cause the sides 32 and 34 to bulge In one embodiment, oxygen is removed from the chamber outward. Because the center portion of the Stack is hotter, it during pressing, Since titanium oxidizes at high temperatures is also Softer. As a result, more bulge will generally occur in and oxygen may affect the process. Pumping inert gas into the softer inner layers 58 as shown in FIG. 5A. Alternative the chamber is one acceptable technique, but other methods types of application of the force may cause Slightly different that remove oxygen from around the metal pieces may also shapes or bulging to occur in the chamber 10. For example, be used. impact hammering may cause slightly more bulging at the Once the chamber 10 is filled with inert gas, or otherwise top and bottom, whereas rolling may cause a more uniform evacuated of oxygen, it is then placed into a furnace to heat bulge. Different types of machines for applying the force the capsule 10 and the plates 24, 26 therein to a selected will cause different reactions in the laminate inside the temperature. In the case of titanium alloy, the preferred chamber 10. temperature is in the range of 1700-2000 F. The tempera 15 In some embodiments, the chamber 10 is then placed into ture is Selected to be Sufficiently high to permit bonding of the forge again and reheated and the preSSure Steps repeated, the layers into a single laminate and yet is not So high that once again pressing the chamber 10 on the top Surface 28 the pure titanium becomes liquid or too soft to hold firm between dies 40 and 42 while it is hot. As shown in FIG. 5B, shape during the lamination process. The temperature is the chamber is then rotated 90° about an axis extending selected to be sufficiently high to facilitate bonding of the through the handle 22 so that the sides 32 and 34 are between titanium layers to each other to form the Single laminate the dies 40 and 42. The chamber 10 is pressed on the sides piece, without each of the layerS losing their individual 32 and 34 So as to return the chamber to rectangular shape, characteristics, Such as color, position, etc. pressing in the bulges that have occurred during the previous When the chamber and its contents have reached a stable pressing Steps. temperature inside the forge, the chamber 10 is removed 25 The laminate is now bonded in the form of a single billet from the forge. A preSSure is then applied to cause the plates of metal. It is desired to remove the billet from the chamber 24, 26 to bond to each other, forming, thereby, a Single billet 10. This is done by cutting the chamber 10 open by any of laminated metal plates. In one acceptable technique, as acceptable method, Such as a Saw, cutting torch, or other illustrated in FIG. 4A, a high pressure hydraulic press 39 is technique. The chamber 10 may then be discarded leaving a used to apply force to the chamber 10. A die 40 is placed on billet of a laminate metal structure of titanium layers 58 in the anvil of the high-pressure hydraulic press, and a die 42 a single integral piece. is placed on the Stand 41 and force is applied to the chamber One purpose of the chamber 10 and the gas 38 is to 10 having the metal plates therein. Sufficient force is applied prevent any reactive gasses, Such as oxygen, from interfer so as to slightly deform the chamber 10. For example, it may ing with the bond between the plates 24, 26 of the billet, or be pressed with sufficient force to reduce the height in the 35 from reacting with the heat to form oxides on Surfaces of the range of around /s-ys inch, with /4 inch being preferred. The plates. According to one embodiment, the chamber is hydraulic press may exert in the range of 5 to 15 tons of formed from a titanium tube of a desired profile, into which force in Such an example. In an alternative embodiment, the are Stacked additional titanium and titanium alloy plates. force may be applied by Some other acceptable technique. Alternatively, the chamber may be formed of individual For example, Steel rollers, impact hammers, hammering by 40 pieces of titanium joined together to form an enclosure. hand, or Some other technique of applying Sufficient force to Thus, this Structure can be considered a chamber only in the bond the plates 24 and 26 to each other may be employed. broadest Sense of being a Structure that facilitates the This will also cause the sides of the chamber 10 to bulge and removal or displacement of oxygen. The chamber is heated Some of the metal in the middle portion may become slightly 45 and pressed as described above with reference to FIGS. wider than their initial width of 1/4 inches. 4A-5B. An advantage of this embodiment is that the billet If the hole 13 was not previously closed, the preceding need not be removed from the chamber, but rather, the preSSure Step is usually Sufficient to have closed the hole. In chamber becomes part of the billet. If it is desired, the side any event, the plates 24, 26 are now bonded, So the pumped surfaces of the billet, corresponding to the sides 32 and 34 gas is no longer necessary. 50 of the chamber of FIG. 1, may be removed to reveal the FIG. 4B illustrates an alternative shape for the dies 40 and layers of metal. Alternatively, the Sides may be left on as part 42. Rather than being a flat die that matches the shape of the of the billet, or removed at a later Stage of manufacturing of top surface 28 of the chamber 10, it can be a square die the billet into a final product. having a Surface area Substantially Smaller than the area of AS shown in FIG. 6, a Single piece of metal composed of the top or bottom surfaces 28, 30 of the chamber 10. In other 55 layers 58 has been obtained through the heat and pressure embodiments, the dies 40 and 42 may be spherical, conical, steps. The plates 24, 26 are now fully bonded and any further Semi-round, or have other shapes as desired. In those treatment is on the unified metal billet 50 having an upper embodiments where the Surface area of the dies used to surface 54. For purposes of clarity and economy, FIGS. 5-13 apply pressure is Smaller than the Surface areas of the do not show the billet 50 as comprising dark and light layers respective surface 28, 30 of the chamber 10, the pressure is 60 representing different metal alloys, but only show lines 51 applied repeatedly to the chamber 10, progressing over the indicating boundaries between layers 58. However, it will be entire Surface of the chamber, Such that the entire top and understood that each of the layers 58 of metal in the billet 50 bottom surfaces 28, 30 of the chamber 10 are subjected to will retain the appearance and characteristics of the particu the requisite pressure to effect the bonding of the plates 24, lar metal or alloy plate from which it was formed. 26. 65 As shown in FIG. 7, according to one technique, the billet FIG. 5A illustrates the interior of the chamber 10 while 50 is further shaped by appropriate rolling, pressing, or other force is being applied by hydraulic press 39. Under the techniques to flatten and shape it as desired. For example, it US 6,857,558 B2 7 8 may be cold rolled or flattened to have a final length of The final piece can be made to have an artistic design 30-40 inches and a final thickness in the range of /2 to 1% based on the color and Selected patterns of the various alloys inches. Other metal working techniques may also be used to as well as the patterns that have been pressed or formed achieve a desired final shape for the billet, including pound therein. It may be used to produce a wide range of finished ing with a hammer on an anvil, pressing, hot rolling or other products. For example, it may be used for the handle of a techniques. knife. It may be used for jewelry, Such as rings, necklaces, pendants, pins, or other decorative metal ornaments. It may FIG. 8 shows an image being impressed into the upper be used as a functional metal part and also as artwork on surface 54 of the final billet using a die having a desired motorcycles, Such as handles, exhaust pipes, or other deco pattern. In the embodiment illustrated, a triangular profile is rative metal ware. pressed into the final billet 50, after which it is machined to The invention has been described with reference to flat remove the upper Surface and expose a decorative Surface 55 plates or layers 24, 26 in the chamber 10, as illustrated in based on the pattern that has been pressed therein. Other FIGS. 1-13. It will be recognized that other shapes and profiles may be pressed into the final billet, including Square, patterns of material may be positioned within the chamber. round or oval profiles, or the like. Once the appropriate A very simple forge-weld can be created using only two image has been pressed therein, the billet is processed to 15 pieces of metal. Complex patterns can be created using expose the underlying layers, Such as by grinding, cutting, or different shapes and types of metal. FIGS. 14A, 14B and other machine techniques, as shown in FIG. 9. 14C illustrate many configurations that are possible. FIG. The shape pressed into the billet may have any desired 14A shows an end view of the chamber 10 in which design, Such as a Symbol or logo. FIG. 10 shows a plan view rectangular bars of two different compositions 62, 64 are of a portion of a billet 50 such as the billet 50 pictured in positioned in a herringbone pattern. It is not necessary for FIG. 7, into the surface 54 of which a box shape 56 has been the metals to be the same amount of each other or alternating impressed. FIG. 11 shows, in cross section, the billet 50, in position. Rather, the same type of metal may be in greater with the impression 56 in the surface 54, and the effects quantities than other types of metal or two metals of the thereof on the underlying layers 58. FIG. 12 shows the billet 25 Same type may be adjacent to each other. For example 30% 50 after a selected amount of Surface 54 has been removed, of one type of metal and 70% of another type of metal may as described with reference to FIGS. 7 and 8, exposing the be used. FIG. 14B shows the chamber 10 in which round decorative surface 55, including lines 60 formed by the bars of two different compositions 66, 68 are alternated, with underlying layers 58. FIG. 13, shows a cross section of the square bars 70 of a third composition positioned in the billet 50 of FIG. 12, illustrating exposure of the surface 55 interstices between the round bars 66, 68. Other patterns and the underlying layers 58 caused by the removal of the include checkerboard, parquet, and concentric, in which Surface 54 to form lines 60. round or Square tubing of Various dimensions is placed, one After the billet has been appropriately shaped and deco tube within another, in the chamber 10. rated according to a desired aesthetic or artistic treatment, as FIG. 14C illustrates another alternative embodiment of a shown in FIGS. 7-13, it may be treated by other artistic 35 regular pattern of metals placed in the chamber 10. In the techniques. For example, it may be anodized at different example of FIG. 14C, numerous types of metals are Voltages in order to provide a desired color pattern, tint or provided, in a regular arrangement which is non-uniform. other effect. Additionally, heating at a medium temperature, First metals 72 and 76 are stacked in the pattern as shown for example 1,000 F., causes the titanium to take a rainbow adjacent to which can be the same type of metal or, alter appearance. Treating at higher temperatures causes it to 40 natively a second type of metal 74. If desired, a rod 78 of the darken Somewhat, while treating at lower temperatures same types of metal of 72 and 76 or alternatively a different results in a lighter Somewhat different pattern. type of metal may also be present in the chamber 10. In some Heat, in the presence of oxygen will cause titanium to embodiments, a powder 84 may exist around the rod 78 and oxidize. Different alloys of titanium will oxidize to a greater in other portions of the chamber So as to provide an or lesser degree at any given temperature, depending upon 45 additional metal. The powder 84 can be the same type of the presence of other metals, and depending upon the total metal as other metals or, alternatively may be of a different percentage of titanium in the alloy. Thus, by heating the alloy or other metal in powder form. Of course, the embodi billet in open air, the exposed portions of the layers of ments of FIGS. 14A and 14B can also have powder metal titanium and its various alloys can be made to react to the interspersed between the various layerS and Solid metal oxygen in the air to take on contrasting colors and Shades, 50 members and still fall within the embodiments of the present for aesthetic appeal. invention. AS also shown in FIG. 14C, additional metals 82 Other treatments, Such as heating while applying pressure, and 80 may also be present within the chamber 10 so that a twisting with or without heat, elongating, compressing, or plurality of different types of metals are forge welded other techniques, may be used in order to impart a desired together as explained herein. In Some embodiments, Voids artistic pattern into the billet. These techniques may be used 55 may be present, Such as Void 86 So as to create a desired on the billet at various Stages in order to create different pattern. Alternatively, no voids are present in the chamber effects. For example, it may be applied to the billet of FIG. and, to the extent possible the chamber is filled with metallic 6, the shaped billet of FIG. 7, or the billets of FIGS. 8–13 alloys of a particular type according to a desired end pattern. having a pattern impressed therein. Of course, in many Thus, as shown in FIGS. 14A, 14B and 14C a plurality of embodiments, the elongated billet 50 of FIG. 7 with the 60 different metals may be arranged in a regular pattern within appropriate heat treatments will already have a desired the chamber in order to achieve a desired final result using appearance, and additional patterns need not be formed; the forge welding techniques as explained herein. The rather, the machining of the billet 50 to produce a finished number of possible configurations is virtually infinite, with product will create the artistic pattern without any further each configuration resulting in a unique pattern in a finished treatment. For example, the taperS and bevels that are part of 65 product. the shape of a knife handle or a piece of jewelry will The invention has the advantage of being composed of a naturally expose layers in interesting and appealing patterns. lightweight, hard, and highly useful metal. It may be used in US 6,857,558 B2 10 any application for which titanium alone is used since it has All of the above U.S. patents, U.S. patent application Similar properties, characteristics, and hardness of titanium publications, U.S. patent applications, foreign patents, for or of a titanium alloy. It thus may be the functional metal eign patent applications and non-patent publications referred piece for any application in which a strong, lightweight to in this specification or listed in the Application Data metal part might be used. This ranges from metal blades for Sheet, are incorporated herein by reference, in their entirety. Scissors, knives, gun barrels, and plate metal, to the metal parts for motorcycles, bicycles, automobiles, racecars, From the foregoing it will be appreciated that, although airplanes, and other products that use titanium as a structure specific embodiments of the invention have been described component. herein for purposes of illustration, various modifications The invention may also have industrial applications, apart may be made without deviating from the Spirit and Scope of from the decorative and artistic appearance it lends to the invention. Accordingly, the invention is not limited functional components. It has been observed that forge except as by the appended claims. welded composites often combine the advantageous char We claim: acteristics of their component layers in a single piece. 1. A method, comprising: Similarly, various titanium alloys have different advantages. arranging first and Second metal pieces in an enclosure, For example, one alloy may have a greater flexibility than 15 each of the first and Second metal pieces comprising a pure titanium or other titanium alloys, while another alloy is percentage of titanium; harder than pure titanium or other alloys. A third alloy may replacing gasses in the enclosure with inert gas, have Superior tensile Strength characteristics. Preliminary heating the enclosure and the first and Second metal tests Suggest that combinations of titanium alloys in forge pieces, and welded composites, according to the invention, impart their mechanically pressing the enclosure on a first axis with a respective characteristics to the final product. Thus, it is force Sufficient to cause the first and Second metal reasonable to expect that titanium parts of hitherto unattain pieces to forge-weld together. able combined characteristics of Strength, hardness, 2. The method of claim 1 wherein the first metal piece is flexibility, or other desirable characteristics may be possible, 25 one of a first plurality of metal pieces, and the Second metal by practice of the principles of the present invention. piece is one of a Second plurality of metal pieces, and The invention has been described with reference to a wherein the arranging Step comprises interleaving the first chamber having dimensions of around 2x4x10 inches. It will and Second pluralities of metal pieces with each other. be understood that the same principles may be applied to 3. The method of claim 2 wherein the first and second manufacture large laminated panels or blocks of titanium. pluralities of metal pieces are metallurgically dissimilar Using industrial equipment commonly available, panels or from each other. blocks having dimensions of many feet on a side may be 4. The method of claim 1 wherein: produced in accordance with the principles of the invention, the first metal piece is one of a plurality of metal pieces and at relatively low costs. Such panels and blockS may find in powder form; many industrial applications, Such as in the aerospace 35 industry, where their unique and Selectable characteristics the plurality of metal pieces are formed from a metal may provide Significant advantages over conventional mate containing titanium; and the first plurality of pieces and the Second piece are rials for the manufacture of parts. chemically different from each other. For example, for a particular component in an airplane 5. A method, comprising: wing, an alloy having desirable characteristics of flexibility 40 is chosen. However, the same alloy may not have an arranging first and Second pluralities of metal pieces in a adequate degree of tensile Strength, So the component must regular configuration Such that the each of the first be made more massive than is optimal, to impart the plurality of pieces is adjacent to and interleaved with necessary Strength. In contrast, it may be possible to lami individuals of the Second plurality of pieces, wherein nate layers of an alloy having the desirable flexibility with 45 each of the first plurality of pieces is formed of a first an alloy having Superior Strength characteristics to manu composition of metal including titanium and wherein facture a part that shares both virtues, and thus enable the use each of the Second plurality of pieces is formed of a of a component having lower mass and weight that Still Second composition of metal including titanium, dif exceeds the functional requirements of the component. ferent from the first composition; Reduction of mass and weight is a constant and endleSS 50 Surrounding the first and Second pluralities of metal pieces endeavor in aerospace products. with an inert gas, In the preferred embodiment, titanium and a titanium heating the first and Second pluralities of metal pieces to alloy are used as two alternating layers in composing the a temperature exceeding 1000 F.; and final billet 50. Alternatively, more than two different mate pressing, while the first and Second pluralities of metal rials or alloys may be used. Such a use may include titanium 55 pieces are Surrounded with the inert gas, the first and and two or more different alloys, each having different Second pluralities of metal pieces together with a force, characteristics. In further alternative embodiments, other Such that a bond is formed between adjacent pieces, metals besides titanium are used. Titanium is advantageous forming a single billet of metal. because it has the properties of being light in weight, 6. The method of claim 5, further comprising the step of noncorrosive in the elements, and non-magnetic. It may be 60 arranging a third plurality of metal pieces in a regular desired to Select a combination of metals that can be configuration adjacent to and interleaved with the first and anodized to cause contrasting color variations between the Second pluralities of metal pieces, wherein each of the third metals, or that can otherwise be heat treated or hardened to plurality of pieces is formed of a third composition of metal vary the Structural properties, as well as impart various including titanium, different from the first and Second com patterns. Other metals that may be used include cobalt-based 65 positions. alloys, as well as other metals that have acceptable proper 7. The method of claim 5, wherein the arranging step ties for the end uses as described herein. includes the Steps of placing the first and Second pluralities US 6,857,558 B2 11 12 of metal pieces within a metal enclosure, wherein the anodizing the billet at a Selected Voltage. Surrounding Step includes pumping the inert gas into the 24. The method of claim 22 wherein the treating step enclosure through a first opening in the enclosure while includes oxidizing the billet at a Selected temperature. venting atmosphere from the enclosure through a Second 25. A method, comprising: opening in the enclosure, and wherein the pressing Step organizing each of a plurality of metal pieces into an includes pressing the enclosure. arrangement Selected to produce an aesthetically pleas 8. The method of claim 7, further comprising removing the billet from the enclosure. ing result, each of the plurality of metal pieces being 9. The method of claim 7 wherein the enclosure includes formed of a metal containing titanium; a handle affixed to an exterior Surface of the enclosure. 1O replacing oxygen gas from around the arrangement with 10. The method of claim 8 wherein the handle comprises inert gas, a pipe having first and Second mouths at respective first and heating the arrangement; and second ends thereof, the first end of the pipe affixed to the pressing the arrangement with a pressure Sufficient to exterior Surface of the enclosure Such that the first opening cause each of the plurality of metal pieces to bond to in the enclosure opens into the first mouth of the pipe, and 15 wherein the pumping Step includes pumping the inert gas those pieces of the plurality immediately contiguous into the Second mouth of the pipe, Such that the gas passes thereto. through the pipe and into the enclosure via the first opening. 26. The method of claim 25 wherein the organizing step 11. The method of claim 7 wherein the enclosure com comprises enclosing the arrangement in a metal enclosure, prises a Section of metal tubing. and wherein the pressing Step includes pressing the enclo 12. The method of claim 7 wherein the enclosure is SUC. titanium. 27. The method of claim 26 wherein the Surrounding step 13. The method of claim 12 wherein the billet includes the comprises pumping the inert gas into the enclosure through enclosure. a first opening therein and venting the enclosure through a 14. The method of claim 5 wherein each of the first and 25 Second opening therein to remove oxygen gas. Second pluralities of metal pieces is in the form of a flat 28. The method of claim 26 wherein the enclosure com plate, and wherein the arranging Step comprises forming a prises Such ones of the plurality of metal pieces as are Stack of alternating pieces of the first and Second pluralities positioned on an outer perimeter of the arrangement. of pieces. 29. The method of claim 25 wherein each of a first portion 15. The method of claim 5 wherein the pressing step of the plurality of metal pieces is formed of a metal having comprises pressing the first and Second pluralities of metal a chemical composition different from each of a Second pieces on a first axis and pressing the first and second portion of the plurality. pluralities of metal pieces on a Second axis. 30. The method of claim 7 wherein the inert gas is argon. 16. The method of claim 5 wherein the pressing step is 31. The method of claim 7 wherein the surrounding step isostatic. 35 is begun prior to beginning the pressing Step, and wherein 17. The method of claim 5 wherein the pressing step is the Surrounding Step is continued after the pressing Step is mechanical. begun. 18. The method of claim 5 further including: repeating the pressing Step. 32. A method, comprising: 19. The method of claim 18 wherein the repeating the 40 arranging first and Second metal pieces in an enclosure; pressing Step includes passing the billet between rollers heating the enclosure and the first and Second metal having a distance therebetween less than a thickness of the pieces, billet. pressing the enclosure with a force Sufficient to cause the 20. The method of claim 5 further comprising: first and Second metal pieces to forge-Weld together; deforming a first Surface of the billet according to a 45 and Selected pattern. replacing gasses in the enclosure with inert gas, the 21. The method of claim 20 further comprising: replacing Step commencing prior to the pressing Step removing a portion of the thickness of the billet, including and continuing until after the pressing Step commences. the first Surface. 50 33. The method of claim 32 wherein the first and second 22. The method of claim 5 further including: metal pieces are ones of first and Second pluralities of metal treating the billet to induce ones of the first plurality of pieces, respectively, and wherein the first and Second plu metal pieces to acquire a first appearance and ones of ralities are dissimilar metals. the Second plurality of metal pieces to acquire a Second 34. The method of claim 32 wherein the first and second appearance. 55 metal pieces each comprises a percentage of titanium. 23. The method of claim 22 wherein the treating step includes: k k k k k