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Lighting &

Corning Incorporated Lighting & Materials Houghton Park CB-08 Corning, New York 14831 tel: 607-974-4331 fax: 607-974-7618 www.corning.com MACOR is a registered trademark of e-mail: [email protected] Corning Incorporated, Corning, NY 14831

MACOR 01 Printed in the U.S.A MACOR® Applications Machinable With MACOR® Machinable Glass Ceramic Ultra-High Vacuum Environments (MGC), fabrication is fast because it can • is MACHINABLE with ordinary metal working tools be machined into complicated shapes MACOR® Machinable Glass Ceramic is used as an • allows FAST TURNAROUND, no post firing required and precision parts with ordinary metal or coil support and for vacuum feed-throughs. In these applications, • holds TIGHT TOLERANCES, up to .0005” working tools, quickly and inexpensively, the conductive materials are supported by the MACOR MGC part and a compatible sealing glass is used to produce a vacuum-tight, • withstands HIGH TEMPERATURE, up to 1000ºC (no load) and it requires no post firing after machining. That means no frustrating . • is CLEAN, no outgasing and zero porosity delays, no expensive hardware, no post fabrication shrinkage, and no costly Constant Vacuum Applications diamond tools to meet specifications. MACOR MGC parts are found in spacers, headers and for microwave devices and as sample holders in field . Properties Aerospace MACOR® Machinable Glass Ceramic has a continuous use temperature Over 200 distinctly shaped MACOR MGC parts can be found on of 800ºC and a peak temperature of 1000ºC. Its coefficient of thermal America’s reusable Space Shuttle Orbiter. Retaining rings of MACOR expansion readily most metals and sealing . It is MGC are used at all hinge points, windows and . nonwetting, exhibits zero porosity, and unlike ductile materials, won’t deform. It is an excellent insulator at high voltages, various frequencies, Also, large pieces of MACOR glass ceramic are used in a NASA MACand high temperatures. When properly baked out, it won’t outgas in CORspaceborne gamma radiation detector. For this application, frame vacuum environments. corners are joined by a combination of machined (butt-lap) mechanical joints and a sealing glass. Machining Machining tolerances are surprisingly tight, up to .0005". It can be Nuclear-Related Experiments machined to a surface finish of less than 20μin. and polished to a Since MACOR MGC is not dimensionally affected by irradiation, smoothness of 0.5μin.-AA. Configurations are limited only by available small cubes of the are machined to a tolerance of one equipment and the experience of the machinist. micron and used as a reference piece to measure dimensional change in other materials. Sealing, Joining and Metalizing MACOR MGC can also be joined or sealed - both to itself and to other Nozzles materials - in a number of ways: metalized parts can be soldered Welding equipment manufacturers are using MACOR MGC together and brazing has proven an effective method of joining the as a nozzle on the tips of oxyacetylene torches. The material’s material to various metals; produces a strong joint, and sealing nonwetting characteristic means molten particles won’t adhere glass creates a vacuum tight seal. Even a straight-forward mechanical to and decrease the effectiveness of the nozzle. joint is possible. The Point is this: When you need the performance of a It can be thick film metalized using metal inks, Fixtures technical ceramic (high use temperature, or thin film metalized by sputtering. MACOR MGC is used as an electrode support and burner block in electrical resistivity, zero porosity) and several industrial high , electrical cutting operations due to its low your application demands the ready thermal conductivity and excellent electrical properties. fabrication of a complicated shape (quickly, precisely, privately), look at Medical Equipment MACOR MGC. It will lower costs and substantially reduce the time between Producers of medical components are intrigued by MACOR MGC’s design and actual use. inertness, precise machinability and dimensional stability.

MACOR 2 Applications 3 Properties Technical Data Modulus of Rupture

The general characteristics of this 20,000 137.9 I. Thermal II. Mechanical material described below were derived from laboratory tests performed by 15,000 103.4 SI/Metric English SI/Metric English Corning from time to time on sample - - - 13.600 ------quantities. Actual characteristics of Minimum specified average value Coefficient of Expansion 2.52 g/cm3 157 lbs/ft3 10,000 68.9 Strength, psi Strength,

-7 -7 production lots may vary. MPa Strength, -200 - 25ºC 74x10 /ºC 41x10 /ºF Porosity 0% 0% -7 -7 25 - 300ºC 93x10 /ºC 52x10 /ºF 6 5,000 34.5 -7 -7 Young’s Modulus, 25ºC 66.9 GPa 9.7x10 psi 25 - 600ºC 114x10 /ºC 63x10 /ºF (Modulus of Elasticity) -7 -7 25 - 800ºC 126x10 /ºC 70x10 /ºF 0.0 Poisson’s Ratio 0.29 0.29 0 200 400 600 800 1000 6 Specific Heat, 25ºC .79 KJ/kgºC 0.19 Btu/lbºF Shear Modulus, 25ºC 25.5GPa 3.7x10 psi Temperature, °C Btu in Thermal Conductivity, 25ºC 1.46 W/mºC 10.16 Hardness, Knopp, 100g 250 250 hr ft2ºF DC Volume Resistivity 12000 17 -7 2 2 Rockwell A 48 48 Thermal Diffusivity, 25ºC 7.3x10 m /s 0.028 ft /hr 16 Modulus of Rupture, 25ºC 94 MPa 13,600 psi 10000 Continuous Operating Temperature 800ºC 1472ºF (Flexural Strength) (minimum specified average value) 15 14 Compressive strength 345 MPa 50,000 psi 8000 Maximum No Load Temperature 1000ºC 1832ºF 13 L/L, ppm

0.5 0.5 Δ 6000 Fracture Toughness 1.53 MPa m 1,390 psi in 12

, ohm-cm 11

4000 p 10 Log Log III. Electrical IV. Chemical 2000 9

Thermal Expansion Thermal Expansion 8 0 SI/Metric English Tests Results 7 -2000 6 Constant, 25°C Weight Loss -200 -100 0 100 200 300 400 500 600 700 800 050 100 150 200 250 300 350 400 450 500 2 1 KHz 6.03 6.03 (mg/cm ) Temperature, °C Temperature, °C 8.5 GHz 5.67 5.67 Solution pH Time Temp. Gravimetric ° 5% HCL 0.1 24 hrs. 95ºC ~ 100 Loss Tangent, 25 C (Hydrochloric Acid) -3 -3 Thermal Conductivity Dielectric Constant 1 KHz 4.7x10 4.7x10 2.0 -3 -3 0.002 N HNO3 2.8 24 hrs. 95ºC ~ 0.6 50 8.5 GHz 7.1x10 7.1x10 (Nitric Acid) 100 Hz 1 KHz

Dielectric Strength (AC) avg. 0.1 N NaHCO3 8.4 24 hrs. 95ºC ~ 0.3 1.8 C 40 (at 12 mil thickness and 25°C) 9.4 KV/mm 785 V/mil ( Bicarbonate) ° 0.02 N Na CO 10.9 6 hrs. 95ºC ~ 0.1 2 3 1.6 (DC) avg. (Sodium ) 30 (at 12 mil thickness and 25°C) 62.4 KV/mm 5206 V/mil 5% NaOH 13.2 6 hrs. 95ºC ~ 10 (Sodium ) 1.4 10 KHz DC Volume Resistivity, 25°C >1016 ohm-cm >1016 ohm-cm 20 Resistance to water over time Dielectric Constant H O 7.6 1 day* 95ºC 0.01 1.2 2 W/m Thermal Conductivity, 10 3 days* 95ºC 0.07 100 KHz 7 days* 95ºC 9.4 1.0 0 *Water not freshened daily 3 days** 95ºC 0.06 0 100 200 300 400 500 600 700 0 100 200 300 400 **Water freshened daily 6 days** 95ºC 0.11 Temperature, °C Temperature, °C

Young’s Modulus Loss Tangent 10.0 10 69.0 1 KHz 10 KHz 100 Hz

9.8 67.6 1

psi 100 KHz 6 9.6 66.2

10-1

9.4 64.8 E, Gpa Loss Tangent Loss

-2

Young’s Modulus, 10 Modulus, Young’s 10 9.2 63.4

9.0 10-3 0 100 200 300 400 500 100 200 300 400 500 Temperature, °C Temperature, °C

Properties 4 Technical Data 5 Machining Composition

Key factors for successful machining are MACOR Machinable Glass Ceramic is a white, odorless, proper machining speeds and coolant. -like (in appearance) material composed of approximately 55% fluorophlogopite mica and 45% . It has no MACOR Machinable Glass Ceramic can known toxic effects; however, the dust created in machining can be be machined with high speed steel tools, an irritant. This irritation can be avoided by good housekeeping but carbide tools are recommended for and appropriate machining techniques. The material contains the longer wear. following compounds:

Achieve the best results by using a water- Approximate soluble coolant, such as Cimstar 40 - Pink, Weight %

especially formulated for cutting and - SiO2 46% grinding glass or . - MgO 17% No post firing is required after machining. Aluminum - Al2O3 16% Potassium - K2O 10% - B2O3 7% - F 4% Grinding Sawing Milling Diamond, silicon- Use a carbide grit blade at a band speed of Cutting speed 20-35 sfm carbide or aluminum- 100 fpm. An alternative is a silicon carbide Chip load .002 ipt oxide grinding wheels or diamond cut-off wheel. Depth of cut .150-.200 in. can be used. Randomly oriented mica flakes in the microstructure of Polishing Turning Drilling MACOR MGC are the Start with loose 400-grit Cutting speed 30-50 sfm Drill size Spindle Speed Feed Rate key to its machinability. silicon carbide on a steel Feed rate .002-.005 ipr 1/4 in. 300 rpm .005 ipr wheel. For the final Depth of cut .150-.250 in. 1/2 250 .007 polish, use cerium oxide 3/4 200 .010 or alumina on a polishing 1 100 .012 pad for glass or ceramics. 2 50 .015 A 0.5μin.-AA finish can Allow at least .050" of extra material on be achieved. the back side for breakout. This excess can be removed after drilling.

Tapping Make clearance holes one size larger than those recommended for metals. Chamfer both ends of the hole to reduce chipping. Run the tap in one direction only. (Turning the tap back and forth can cause chipping.) Continuously flush with water or coolant to clear chips and dust from the tap. Microstructure of MACOR MGC 5000X magnification.

Machining 6 Composition 7