Microstructure and mechanical properties of WMoCu alloy doped with different sized Mo particles

WMoCu alloys doped with Mo particles in the nanoscale or microscale range were prepared by infiltration process using the element Ni as an activating element. A comparative study was carried out on the effects of doping with nano- and micro-scale Mo particles on the microstructure and mechanical properties of WMoCu alloys. The results show that the microstructure and distribution of Mo particles is more uniform in the W60Mo25Cu15(M) alloy doped with 3 μm sized Mo particles. The addition of the activating element Ni promotes mutual diffusion between W, Mo, and Cu. A WMo transition layer is formed at the interface between W and Cu, and a core-shell structure with a thickness of about 2 μm is formed around the W particles, which has an amorphous structure at the interfaces, which increases the deformation resistance during interfacial sliding and improves the bonding strength of the WMoCu alloy. The tensile strength of the W60Mo25Cu15(M) alloy is higher than that of the W60Mo25Cu15(N) alloy and the WCu alloy both at room temperature and at elevated temperature. Especially at a high temperature of 600 °C, the tensile strength of the alloys W60Mo25Cu15(M) and W60Mo25Cu15(N) is increased by 57.44% and 32.64%, respectively, compared to the alloy W85Cu15. The fracture mechanisms of the WMoCu alloy are mainly intergranular fracture and transgranular fracture.