Interfacial evolution mechanism of W/Cu explosive welding interface affected by preheating

Tungsten/copper (W/Cu) laminated composites possess high application potential in electronic, aerospace, and nuclear industries by combining the advantages of W and Cu. Among various fabrication methods, the explosive welding method is regarded as one rapid and cost-effective approach to producing W/Cu laminated composites considering the huge differences in physical properties between W and Cu. However, the lack of investigation on the bonding interface evolution between thick W plate and Cu plate inhibits the potential application of explosive welding on the large-scale production of the W/Cu laminated composites. In this study, the crack-free thick W/Cu laminated composites have been obtained successfully through the hot explosive welding approach, and the evolution mechanism of wavy interface formation is studied through numerical simulation and experimental investigation. The microstructure of welded W/Cu interface zone is further characterized to analyze the evolution mechanism of the wavy interface and corresponding bonding features. Moreover, the results of the mechanical property tests, such as compression shear, direct tensile, and micro-hardness tests, demonstrate that the welded W/Cu laminated composite features outstanding mechanical properties. Our study reveals the formation mechanism of the W/Cu interface during the hot explosive welding process and provides a rapid and efficient strategy to produce large-size W/Cu laminated composite with a thick W layer.