The Characteristics of Tungsten Copper Alloy

The machining and grinding characteristics of tungsten alloy are similar to those of hard grey cast iron. Being nonporous, standard water soluble coolants may be used if desired, but are not required. Each machine shop usually has its individual machining or grinding practice and, therefore, the information presented should be considered as a guide only.
Tool: Carballoy, grade 883 or equivalent. Grind tools with 0 deg. rake, 8-12 deg. clearance, and .010" to .025" nose radius. The nose radius can increase with the size of the work. For fine finish, stone small flat on tool parallel to work. Suggest resting stone on work when honing tool.
Turning & Boring: Roughing, approximately .030" deep and .020" per revolution feed. Finishing, .002" to.005" depth of cut and .001" to .002" per revolution feed. Turning speed, 300-500 surface feet per minute. Do not use lubricant or coolant.
Shaping: Tool Speed: 43" per minute for Tungsten Copper 25% alloy.
Depth of Cut: .030"
Feed: .020" per stroke
Milling: Drilling High Speed steel drills and taps may be used.
Through Tapping: Holes are recommended. Material must be firmly held. Hand feed-lubricant and cutting oil acceptable.
Rough Grinding: is best done with 80 grit resin bonded wheels of medium hardness; .015" per pass on Tungsten Copper 25% alloy.
Use water or water soluble oil coolant.
Joining: Material may be silver brazed, or copper brazed in a hydrogen atmosphere.
Copper Tungsten alloy is the composite of Tungsten and Copper, which own the excellent performances of Tungsten and Copper, such as heat-resistant, ablate-resistant, high-intensity, excellent thermal and electrical conductivity. It is easy to be machined. It is used widely in such industries as engine, electrical power, electron, metallurgy, spaceflight and aviation. Using CIP formation, sintered tungsten skeleton and infiltrating copper (silver) technology, large size and special shape products of tungsten-copper (silver) composites with 6-90 percent of copper are produced, such as electric contacts, electrode, refractory parts, heat sinks and parts of rocket, We can also produce sheet material, tubing, plate and other small products by mould pressing, extrusion pressing and MIM.
Tungsten copper alloys are used where the combination of high heat resistance, high electrical and/or thermal conductivity, and low thermal expansion are needed. Some of the applications are in electric resistance welding, as electrical contacts, and as heat sinks. As contact material the alloy is resistant to erosion by electric arc. WCu alloys are also used in electrodes for electrical discharge machining and electrochemical machining.
The CuW75 alloy, with 75% of tungsten, is widely used in chip carriers, substrates, flanges and frames for power semiconductor devices. The high thermal conductivity of copper together with the low thermal expansion of tungsten allows thermal expansion matching to silicon, gallium arsenide, and some ceramics. Other materials for this applications are CuMo alloy, AlSiC, and Dymalloy.