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

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 micr...

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Autori principali: Kota Kurabayashi, Shun Tokita, Yutaka S. Sato
Natura: Articolo
Lingua:English
Pubblicazione: MDPI AG 2022-03-01
Serie:Metals
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Accesso online:https://www.mdpi.com/2075-4701/12/3/453
Descrizione
Riassunto: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, although the thickness of the IMC layer increased. The IMC layer formed at the Al/Cu interface without Ni comprised CuAl<sub>2</sub> and Cu<sub>9</sub>Al<sub>4</sub> from the pure Al side. In contrast, the IMC layer formed with 3 at.% Ni consisted of (Ni,Cu)Al, CuAl, and Cu<sub>9</sub>Al<sub>4</sub> from the Al side. The addition of Ni eliminated the weak CuAl<sub>2</sub>/Cu<sub>9</sub>Al<sub>4</sub> 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.
ISSN:2075-4701