Effects of reinforcing tungsten fibers and skeleton pre-sintering temperature on microstructure, mechanical and electrical properties of ultrafine-grained tungsten‑copper composites

Abstract

In this work, ultrafine-grained Wf/WCu composites have been developed in this work using skeleton pre-sintering at respective 1050 °C, 1150 °C, 1250 °C and 1350 °C followed by infiltration under a reductive hydrogen atmosphere. The resulted microstructure including sinterability, grain orientation distribution and phase constituents, the resulted mechanical properties including microhardness and compressive behaviors, as well as the resulted electrical properties including electrical conductivity and high-voltage arcing resistant behaviors were systematically investigated in comparison. Results revealed that the composite pre-sintered at 1250 °C exhibited the best comprehensive properties including the highest hardness of 659 HV0.05 for Wf and 267 HV0.05 for WCu matrix, the highest compressive strength of 1004.6 MPa with pronounced deformation plasticity of 25.8%, as well as a good electrical conductivity of 24.4 %IACS and the highest electrical breakdown strength of 6.80 × 107 V/m.