Enhanced strength and ductility in dissimilar friction stir butt welded Al/Cu joints by addition of a cold-spray Ni interlayer

Abstract

Abstract In this study, commercially pure Cu plate was cold sprayed with a 90 μm thick Ni coating and friction stir welded to an Al 6061 alloy plate in a butt joint configuration. The joint interface was characterized by optical microscopy and scanning electron microscopy and was compared to the joint without a Ni coating. The results show that the joint mechanical strength was significantly improved with a Ni interlayer. The average peak stress and the elongation of the joint with Ni coating reached 190 MPa and 14 %, respectively. The formation of intermetallic compounds at the interface was clearly suppressed with a Ni coating compared to the directly welded sheets.