The influence of pre-sintering temperature on the microstructure and properties of infiltrated ultrafine-grained tungsten-copper composites

Abstract In this work, several ultrafine-grained W–Cu composites were prepared by sintering at different temperatures of 1050 °C, 1150 °C, 1250 °C and 1350 °C of 2 h followed by traditional infiltration. The sintering kinetics of tungsten particles, as well as the resultant density, mechanical properties including hardness and compressive behavior, and electrical properties including electrical conductivity and arc erosion behavior of the infiltrated composites were investigated comparatively. Results revealed that the composite pre-sintered at 1250 °C with the highest tungsten particle contiguity of 0.45 exhibited the highest hardness of 272 HV and compressive strength of 894.0 MPa with a pronounced deformation plasticity; besides, the good sinterability of its microstructure contributed to a well dispersed arc spots over 50 times of electrical breakdown tests, resulting in a superior and reliable electrical breakdown strength of 5.66 × 107 V/m.