W-Cu composites with submicron- and nanostructures: progress and challenges

W-Cu composite materials are widely used in civilian industries and aerospace fields owing to their integrated properties of high hardness, wear and arc resistance, electrical and thermal conductivities, and low coefficient of thermal expansion. The recently developed submicron- and nanostructured W-Cu composites exhibit superior performance compared to their conventional coarse-grained counterparts and are expected to further expand applications of this group of materials. This review is focused on recent important progress in the preparation, characterization, and mechanical and physical properties of W-Cu composites with refined structures. We summarize the technologies that are capable of refining component structures and evaluate their advantages and limitations. Furthermore, the effects of component refinement and additives such as alloying elements and dispersed particles on the comprehensive performance of W-Cu composites are demonstrated. At the end of the review, we propose potential research issues and directions worthy of attention for the future development of W-Cu composites.