Microstructure and thermal property of W/Cu multilayer composites

Abstract

In this study, a series of W/Cu multilayer composites were prepared by W and Cu foils bonded at temperatures ranging from 700 to 900 °C through field assisted sintering technique. The microstructure, bending property, thermal conductivity and thermal diffusivity of the W/Cu multilayer composites were investigated. The microstructure in the W layer is similar and the grains grow larger in the Cu layer with increasing bonding temperature. And the interfacial defects between the W layer and Cu layer decrease as the bonding temperature increases. Therefore, the interfacial bonding strength increases as the bonding temperature increases. The interfacial debonding disappears in the W/Cu multilayer composites bonded at 900 °C during three-point bending. Meanwhile, the W/Cu multilayer composites bonded at 900 °C show the highest thermal conductivity (234.6 W/(m⋅K). In addition, the thermal conductivity decreases with the increase of test temperature. The thermal expansion coefficient of the W/Cu multilayer composites bonded at 700 °C is highest. And the model showing the thermal expansion of the W/Cu multilayer composites has been proposed.