Fabrication of W–20Cu composite with optimization of particle packing in PM route

Abstract

The optimal design about the packing structure of W and Cu particles has become a focus of attention for developing the high performance W–Cu composites. In the present work, a series of numerical simulations and physical experiments were conducted to optimize the packing structure of W and Cu particles and establish the relation between particle size and sintering properties. The results reveal that the relative density and uniformity of the binary W–20Cu system showed a negative correlation with increasing size ratio of W and Cu particles. The optimal binary W–20Cu system can be formed when the size ratio of W/Cu particle is 1.5 and the peaked uniformity can reach 0.986. The (W45–20Cu30)-20(W10–20Cu10) size ratio in ternary W–20Cu mixture was identified as the best packing structure by optimization calculation for multi-component system. The relative density of best ternary (W45–20Cu30)-20(W10–20Cu10) system can reach 0.625, which was 10.7% higher than that of binary W45–20Cu30 system. In the best packing structure with size ratio, the sintering properties of ternary W–20Cu composites were efficiently improved by reducing particle size. The W–20Cu composite with small particles showed a tensile/compressive strength over 147/442 MPa (1.73/1.62 times that of the W–20Cu composite with large particles), an electrical conductivity of 36 %IACS, and a hardness of 190 HV. These highlighted results can provide some valuable references for the design and optimization of high performance W–Cu composite in the route of powder metallurgy.