Tungsten–Copper (W–Cu) is a pseudo-alloy composed of tungsten (W) and copper (Cu) that do not form a true solid solution. Instead, it is produced by powder metallurgy, combining tungsten’s refractory strength with copper’s excellent electrical and thermal conductivity.
Because tungsten and copper are mutually insoluble, W–Cu materials consist of a tungsten skeleton infiltrated with copper, forming a metal–metal composite with unique performance characteristics.
Strengthening & Metallurgical Behavior
Microstructure
Interpenetrating W–Cu network
Tungsten provides mechanical rigidity
Copper provides thermal and electrical pathways
Strengthening Mechanisms
✔ Load-bearing tungsten framework
✔ Particle reinforcement (W phase)
✔ Limited work hardening
✔ Grain size control in tungsten skeleton
Failure Modes
Copper phase softening at elevated temperature
Tungsten grain fracture under extreme stress
Refining & Processing Properties
Primary Manufacturing Route – Copper Infiltration
Tungsten powder pressing and sintering
Porous tungsten skeleton formation
Molten copper infiltration
Secondary heat treatment and sizing
Alternate Processing
Powder metallurgy (hot pressing or HIP)
Machinability
✔ Better than pure tungsten
✔ More difficult than WNiFe / WNiCu alloys
✔ Carbide or diamond tools recommended
✔ EDM highly effective
Available Forms
✔ Plates and sheets
✔ Rods and bars
✔ Blocks and slabs
✔ Electrical contacts
✔ Heat sink bases
✔ Precision-machined components
Key Characteristics
✔ Extremely high arc-erosion resistance
✔ Excellent thermal shock resistance
✔ High electrical and thermal conductivity
✔ Low coefficient of thermal expansion (CTE)
✔ Non-magnetic
✔ Stable under repeated arcing
Limitations
Not weldable by conventional methods
Lower ductility compared to heavy alloys
Copper phase limits ultra-high-temperature use
Typical Applications
Electrical & Power: High-voltage switch contacts, circuit breakers, arc contacts, resistance welding electrodes
Electronics & Semiconductor: Heat sinks, power module baseplates, IGBT & MOSFET substrates, microwave packages
Aerospace & Defense: Thermal management components, rocket nozzle inserts, discharge components
Industrial: EDM electrodes, brazing fixtures, high-heat tooling
Why Choose Tungsten–Copper (W–Cu)?
Choose W–Cu pseudo-alloys when high electrical and thermal conductivity, intense arcing resistance, controlled thermal expansion, rapid heat dissipation, and non-magnetic behavior are required in demanding environments.
Comparison with Other Tungsten Materials
Pure Tungsten – Very high strength, low conductivity, very high temperature capability
WNiFe – Good strength and ductility, moderate conductivity
WNiCu – High conductivity, very good ductility
W–Cu – Very high conductivity, excellent arc resistance, medium strength