Tungsten–Copper alloys (CuW or W–Cu) are metal matrix composites produced by combining tungsten and copper powders into a two-phase structure. Since tungsten and copper are mutually insoluble, these materials are composites rather than true alloys, combining tungsten’s high temperature strength and erosion resistance with copper’s excellent electrical and thermal conductivity.
Typical Compositions
| Designation | Approx. Composition (wt%) |
|---|---|
| W50 / Cu50 | 50% Tungsten – 50% Copper |
| W60 / Cu40 | 60% Tungsten – 40% Copper |
| W70 / Cu30 | 70% Tungsten – 30% Copper |
| W80 / Cu20 | 80% Tungsten – 20% Copper |
| W90 / Cu10 | 90% Tungsten – 10% Copper |
Key Physical Properties
| Property | Typical Range | Notes |
|---|---|---|
| Density | 11.85 – 16.75 g/cm³ | Increases with tungsten content |
| Thermal Conductivity | 170 – 250 W/m·K | Excellent heat dissipation |
| Electrical Conductivity | 30 – 60% IACS | Higher Cu → higher conductivity |
| Thermal Expansion | Low | Improved dimensional stability |
| Arc Resistance | Excellent | Resists erosion & thermal shock |
Mechanical Properties
With increasing tungsten content, hardness and strength rise while ductility decreases. Typical tensile strengths range from 500–800 MPa, and hardness may reach ~260 HB in high-tungsten grades. Wear resistance improves significantly with higher tungsten proportions.
Strengthening & Metallurgical Behavior
W–Cu materials consist of discrete tungsten grains embedded in a continuous copper matrix. Because no solid solution forms, properties are governed by phase distribution and volume fraction rather than alloy chemistry.
Higher copper content improves conductivity and machinability, while higher tungsten content increases density, stiffness, and thermal stability. This balance allows designers to tailor the material for specific electrical or thermal demands.
Refining & Processing
Powder blending and compaction
Tungsten skeleton sintering
Copper liquid phase infiltration
Final densification and precision machining
Available Forms
Rods & bars
Sheets & plates
Blocks, discs & rings
Heat sink profiles
Precision machined components
Key Characteristics
✔ High thermal conductivity
✔ Good electrical conductivity
✔ Low thermal expansion
✔ Excellent arc & erosion resistance
✔ High density & stiffness
✔ Better machinability than pure tungsten
Applications
Electrical & Energy
Circuit breaker contacts, vacuum interrupters, welding & EDM electrodes
Thermal Management
Heat sinks, heat spreaders, electronic packaging
Electronics & Power
IGBT modules, EV power systems, semiconductor bases
Industrial
Dies, inserts, furnace components, balancing weights
Advantages of Tungsten Copper Alloys
✔ Balanced conductivity and strength
✔ Excellent arc and wear resistance
✔ Stable under thermal cycling
✔ Low expansion mismatch in assemblies
✔ Easier machining than refractory metals
Why Choose W–Cu Alloys?
Tungsten–Copper alloys are selected when high electrical and thermal conductivity must be combined with strength, erosion resistance, and dimensional stability. They outperform pure copper in arc environments and offer far better machinability than pure tungsten, making them indispensable in electrical, thermal, and high-power engineering systems.