In-situ synthesis of core-shell structure W(WC) composite grains in W-Cu composites fabricated by infiltration

WC strengthened W-Cu composites have attracted much attention due to their high hardness, excellent wear resistance and well high-temperature mechanical properties. In this study, a convenient method was proposed to prepare WC strengthened W-Cu composites by in-situ solid-state reaction with binder as carbon source. The stable carbonization process was determined by thermodynamic calculation and experiments. By infiltrating copper into carbonized W skeleton, the W-Cu composite strengthened by core-shell structure W(WC) composite grain showed pure phase composition and uniform microstructure. The carbonized W-Cu composite with 1 wt% PF exhibited higher relative density of 99.4%, higher hardness of 259.7 HV, higher conductivity of 46.9%IACS compared with traditional W-Cu composite. The average friction coefficient (0.58) and mass loss (0.31 g) of carbonized WC-Cu composites 1 wt% PF were lower than those of conventional WC-Cu composites (0.76, 1.56 g). Meanwhile, the high-temperature compressive strength of carbonized W-Cu composite was higher than traditional W-Cu composite. The new method had high feasibility in the aspects of process stability and cost control advantage. (C) 2021 Published by Elsevier B.V.