Effect of Rotation Rate on Microstructure and Properties of Friction Stir Welded Joints of Al/Cu Clad Plates

Abstract

Al/Cu clad plates were joined by friction stir welding (FSW), and the effect of rotation rate on microstructure and mechanical properties of joints was investigated. The results show that the laminar structure of aluminum and copper is generated in the weld. With increase the of rotation rate, the grain sizes of aluminum and copper are increased respectively. The average microhardness of the Al/Cu plates exceeds that of the as-received metal of 33.0 HV, and ultimate tensile strength is 127.21 MPa in the nugget zone when rotation rate is 1180 r/min. The microhardness of copper in the nugget zone is 99.7 HV, reached 82.05% of the microhardness of received metal, and void defect is main reason responsible for the decrease of mechanical properties of joints.

Keywords

• friction stir welding
• Al/Cu clad plates
• rotation rate
• microstructure
• mechanical properties