Mechanical and Metallurgical Behavior of Weld-Bonds of 6061 Aluminum Alloy

Abstract This article presents the microstructure and mechanical properties of spot weld and weld-bond of 2 mm thick 6061 aluminum alloy sheets. The fracture surfaces of the adhesive joints, spot welds, and weld-bonds were studied under scanning electron microscope (SEM). Optical microscopy was carried out to study the microstructure of the joints and nugget size of resistance spot weld and weld-bond of aluminum alloys. Hardness of the weld nugget and HAZ of the spot weld and weld-bond was studied using microhardness tester. Fatigue properties of the adhesive joints, spot welds, and weld-bonds were studied using constant load ratio 0.5. Further, attempts were made to correlate the mechanical properties of various joint with microstructure and nugget size. It was found that optimal combination of process parameters resulted in significantly better mechanical performance of weld-bond than resistance spot weld. Keywords: 6061 aluminum alloyFatigue behaviorMicrohardnessWeld nuggetWeld-bonding