Thermal physical and mechanical properties of W-Cu alloy fabricated via selctive laser melting

Abstract

In this work, the W-(Ni)-Cu composites were fabricated by Selective Laser Melting with the different W content of 60wt.%, 70wt.%, 75wt.% and 80wt.%, respectively. The relative density, microstructure, surface morphology, thermal conductivity, thermal expansion coefficient, roughness and hardness of W-(Ni)-Cu composites were investigated by Archimedes method, scanning electron micrograph, energy disperse spectrum, thermal analyzer, differential scanning calorimeter, white-light interferometer and vickers hardness tester. The results indicated that w th the increase of W content, the homogeneous distribution of W solids evolved to contiguity and connective, densification mechanism transformed from rearrangement densification to solid-state sintering densification which resulted in the decrease of relative density, meanwhile Ni additive was responsible for the enhanced relative density. Whilst the heat transfer path transferred from preferential high conductivity phase (Cu) to the structure consisted of a core of low thermal expansion material (W) and an edge network of high thermal conductivity phase (Cu). The results showed that the thermal conductivity and thermal expansion coefficient (CTE) increased with the Cu content of the composite, while the difference of measured value and theoretical value was increased with the increase of W content. The roughness and hardness were also increased with the increase of W content.In this work, the W-(Ni)-Cu composites were fabricated by Selective Laser Melting with the different W content of 60wt.%, 70wt.%, 75wt.% and 80wt.%, respectively. The relative density, microstructure, surface morphology, thermal conductivity, thermal expansion coefficient, roughness and hardness of W-(Ni)-Cu composites were investigated by Archimedes method, scanning electron micrograph, energy disperse spectrum, thermal analyzer, differential scanning calorimeter, white-light interferometer and vickers hardness tester. The results indicated that w th the increase of W content, the homogeneous distribution of W solids evolved to contiguity and connective, densification mechanism transformed from rearrangement densification to solid-state sintering densification which resulted in the decrease of relative density, meanwhile Ni additive was responsible for the enhanced relative density. Whilst the heat transfer path transferred from preferential high conductivity phase (Cu) to the structure consisted of a co...