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

Abstract

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.