Analysis of the Influence of Starting Materials and Processing Conditions on the Properties of W/Cu Alloys

Effect of Microstructure Refinement on Surface Morphology and Dynamic Mechanical Properties of W-Cu Alloys

Two ultrafine-grained W-Cu alloys and two coarse-grained W-Cu alloys were prepared to study the effect of tungsten grain refinement on the interface characteristics between coating and W-Cu alloys. The experimental results show that in the coarse-grained W-Cu alloys, the tungsten phase near the surface is easy to form pits and cracks during impact loading, while the fine-grained tungsten alloy is not prone to this phenomenon. Simulations show that refining tungsten grains can not only reduce the impact absorption energy, but also increase the contact area of tungsten and copper phases, thereby reducing the fracture probability of tungsten phases and improving the dynamic mechanical properties of the W-Cu alloys under impact loading. The tested results show that the shear strength of gold studs on the coating is increased by about 33%, after grain refinement for the W-Cu alloys.

Enhanced Ductility of a W-30Cu Composite by Improving Microstructure Homogeneity

Due to its negligible solubility, it is difficult to obtain a W-30Cu composite with a homogenous microstructure. However, with a selected W skeleton, a homogeneous phase distribution was achieved for a W-30Cu composite in the present study. By detailed characterization of the mechanical performance and microstructure of the W-30Cu composite, as well as the stress distribution state under a loading condition, the effects of microstructure homogeneity on the mechanical properties and failure mechanisms are identified. The mechanisms by which the ductility and strength depend on microstructure homogeneity contain the effects on plastic deformation and stress coordination of the Cu phase network. The dominant factors for the high ductility and strength of W-30Cu composites are proposed.