Resistance Spot Welding of Aluminum to Aluminum Clad Steel Sheet: Experimental and Theoretical Analysis

Abstract

Abstract In order to increase the cross-tension to the tensile-shear peak load ratio, aluminum clad steel sheet produced by roll bonding, was used for resistance spot welding to Al-Mg aluminum alloy. The results showed that the weld nugget formed between the aluminum clad layer and Al-Mg base sheet was the load bearing area. Presence of the metallurgical bond between the steel sheet and the aluminum clad layer led to the formation of the Al/Fe intermetallic compound with the thickness less than ∼3.5 μm. This narrow intermetallic layer did not play a detrimental role in the weld strength and therefore, the cross-tension to the tensile-shear peak load ratio reached up to ∼0.5 at the maximum tensile-shear peak load which was an advance compared to the results in the literature. Theoretical analysis was relatively successful for prediction of the critical nugget diameter and the tensile-shear peak failure loads. While the tensile-shear peak load increased with the welding current up to ∼4 kN, the peak load in the cross-tension test remained relatively constant at ∼2 kN.