Microstructure and properties of a nanostructured W-31 wt% Cu composite produced by magnetic pulse compaction of bimetallic nanoparticles

Nanostructured W-31wt.%Cu composite was for the first time produced via magnetic pulse compaction from bimetallic particles obtained using electric explosion of intertwisted copper/tungsten wires in argon and then characterized for microstructures, mechanical strength and tribological behavior at high temperatures. Microstructure of the composite is characterized by recrystallized copper grains with mean grain size of 59 +/- 3 nm and unreacted spherical tungsten particles. The composite density was in the range 93-99%. Flexural and compression strengths were 560 +/- 10 and 1035 +/- 150 MPa, respectively. Tribological high temperature tests showed that this composite develops reduced wear starting from the testing at 250 degrees C. Such an adaptation mechanisms is related to generation of copper tungstate CuWO4 on the worn surfaces.