Ultrafine-grained W–Cu–SiC composites prepared by mechanical alloying and infiltration of copper into pre-sintered skeleton

Abstract

In this paper, a combined processing method of mechanical alloying and infiltration was used to prepare the WCu-x wt-%SiC (x = 0.5, 1, 2, 3) composites. The microstructure, density, electrical conductivity and compressive behaviour of the composites were studied comparatively. First a decreasing and then an increasing particle growth trend was obtained, indicating that a small content of SiC below 1 wt-% was beneficial for particle refinement. Besides this, with the increase of the SiC content, both the density and electrical conductivity decreased gradually. Consistent with the particle–particle contiguity of the highest value of 0.404, the WCu-1 wt-%SiC composite showed the best compressive properties. Further electron backscattering diffraction results revealed that the ultrafine-grained SiC particles, which are distributed homogeneously in the composite with lower Schmid factor values would perturb the dislocation motion to make proliferation of more dislocations, exhibiting unordinary strain-hardening during deformation.