Effect of Cu content and heat treatment on the properties and microstructure of W–Cu composites produced by hot extrusion with steel cup

• A efficient method was proposed to produce W–Cu composites with different specifications.
• The copper content has effects on electrical conductivity and hardness.
• Electrical conductivity can be increased by subsequent heat treatment.

In this paper, the effect of Cu content on the properties and microstructure of W–Cu composites produced by hot extrusion with steel cup and heat treatment was investigated. W–Cu products were sintered at 1150 °C under vacuum conditions for 1 h and then the sintered billets were hot extruded with steel cup at 950 °C with extrusion ratio 10.56. After heat treatment, W–Cu composites with highly comprehensive properties will be acquired. Metallographic microscopy and scanning electron microscope were used to observe microstructure. Experimental results showed that when the Cu content (10–20 mass%), a little deformation was observed in W phase. When the percentage composition of Cu is high (30–40 mass%), little deformation appeared in W phase, while main deformation occurred in Cu phase. Tungsten phase contiguity in extruded composites is increasing with the decreasing of Cu content. It is hard to achieve the full densification for W–Cu composite with low Cu content (below 20 wt.%Cu) by plasticity deformation technology with small deformation amount.

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