Thermomechanical processing induced microstructural tuning for synergistic enhancement of structural and functional performance in WCu immiscible composite

WCu composites combine high strength, rigidity, and low thermal expansion coefficient of W with excellent electrical and thermal conductivity of Cu, endowing them with broad application prospects in a broad application. However, the intrinsic immiscibility between W and Cu leads weak interfacial bonding, posing a long-standing challenge to their high-performance applications. Although the introduction of a third component is widely recognized as an effective mean of improving interfacial compatibility, it is often achieved at the expense of electrical and thermal performance. In this study, fine-grained WCu composites were subjected to precisely tailored thermomechanical processing (rolling and annealing). On the one hand, the formation of heterointerface-induced stacking faults was promoted, and the substructures introduced by rolling enhanced the plastic deformability of the W particles. Through these coupled effects, load transfer and dislocation motion across the two phases were effectively regulated, leading to a pronounced improvement in overall mechanical performance. On the other hand, the continuity of the Cu phase was enhanced and charge transport pathways were optimized, thereby resulting in improvement of electrical conductivity. These findings provide new insights into the tuning of phase configurations in immiscible metal composites, offering a viable pathway for the synergistic optimization of multiple properties.