Friction welding of Cr–Zr copper alloy

Summary

Copper and copper alloys have a higher thermal conductivity than even aluminium, itself regarded as having good heat conduction. When materials with high thermal conductivity are joined, the heat rapidly diffuses in the base metal in a way that generally results in poor weldability due to the difficulty of concentrating heat in welds. To obtain sound welds with satisfactory penetration during fusion welding of copper alloys, it is necessary to ensure high-temperature preheating and high interpass temperatures. Copper alloys are also reported to face problems such as solidification cracking and blowhole formation.¹ To solve these problems, it is necessary to perform welding at low heat input for a short time, which are conflicting requirements because of the high heat conduction.