Enhancing comprehensive properties of W/Cu joints through surface grinding and spark plasma sintering

To address the challenges in joining immiscible W/Cu dissimilar metals, this study employs surface grinding to induce plastic deformation and coarsening on the W surface, thereby obtaining the reliable W/Cu joints through spark plasma sintering (SPS). The effects of surface grinding and bonding temperature on the interfacial microstructure, mechanical properties and thermal conductivity of W/Cu joints were systematically investigated. The results demonstrate that the micro-nano structure on the W surface is successfully introduced into the W/Cu interface via surface grinding combined with SPS, forming a serrated interface structure . Shear tests and fracture analysis reveal that this serrated interface structure effectively enhances the mechanical interlocking effect and changes the crack propagation path, thus improving the mechanical properties of W/Cu joints. At 1000 °C, the shear strength of the W/Cu joint after surface grinding reaches 214.17 MPa, which is 55.59 % higher than that of the joint prepared through direct bonding (DB). Furthermore, compared to the DB joint, the W/Cu joint after surface grinding maintains superior high-temperature thermal conductivity , which is 130.11 W/(m·K) at 600 °C. This work proposes a simple and effective mechanical surface treatment method to realize high-performance W/Cu joints. • The micro-nano structure on the W surface is successfully introduced into the W/Cu interface via surface grinding combined with SPS, forming a serrated interface structure. • At 1000 °C, the shear strength of the W/Cu joint after surface grinding reaches 214.17 MPa, which is 55.59 % higher than that of the DB joint. • Compared to the DB joint, the W/Cu joint after surface grinding maintains superior thermal conductivity, which is 130.11 W/(m·K) at 600 °C.