Effect of Ni Addition on the Interfacial Strength of Al/Cu Dissimilar Welds Produced by Friction Stir Lap Welding

Kota Kurabayashi, Shun Tokita, Yutaka S. Sato
2022 Metals  
Al/Cu dissimilar joining is a key technology for reducing the weight and cost of electrical components. In this study, the dissimilar friction stir lap welding (FSLW) of a Ni-containing Al alloy to pure Cu was performed, and the effects of the addition of Ni on the weld strength and interfacial microstructure were examined. A thin intermetallic compound (IMC) layer was observed at the Al/Cu weld interface produced by FSLW. The addition of 3 at.% Ni effectively improved the weld strength,
more » ... h the thickness of the IMC layer increased. The IMC layer formed at the Al/Cu interface without Ni comprised CuAl2 and Cu9Al4 from the pure Al side. In contrast, the IMC layer formed with 3 at.% Ni consisted of (Ni,Cu)Al, CuAl, and Cu9Al4 from the Al side. The addition of Ni eliminated the weak CuAl2/Cu9Al4 interface, thereby improving the weld strength. The results of this study suggest that the strength of the Al/Cu weld can be effectively improved by the thinning of the IMC layer caused by FSLW and the change in interfacial microstructure caused by Ni addition.
doi:10.3390/met12030453 fatcat:ov7vccb7efh3vdtomh72gtuaa4