Strengthening mechanisms and research progress in the W/Cu interfaces

Abstract

Tungsten‑copper (WCu) composites integrate the high melting point, strength, and superior wear and arc resistance of tungsten with the exceptional electrical and thermal conductivity and good plasticity of copper. This combination makes them ideal for applications requiring high thermal conductivity and resistance to high temperatures. However, producing high-quality composites is challenging due to the significant differences in crystal structure and physical properties between tungsten and copper. Under high temperature load conditions, the WCu interface is subjected to substantial thermal stresses, which can lead to crack formation and eventual material failure. This review systematically analyzes methods to enhance the bonding strength of the W/Cu interface, suppress crack initiation and propagation, and mitigate interface thermal stresses. The focus is on physical bonding, chemical bonding, and the design and preparation of WCu functionally graded materials (FGMs). The mechanisms for strengthening the W/Cu interface are elucidated. Additionally, this review addresses the effects of grain refinement and work hardening at the interface on the microstructure and overall properties of WCu composites. Finally, the review summarizes the prospects for W/Cu interface research and highlights the challenges for future investigations.