Effect of Welding Conditions of Spot Welded Zone on the Tensile Strength about Aluminum Alloy (A6061)

It is considered to be available in reducing the weight of automobiles that the aluminum alloy is applied to manufacture them. The spot welding of aluminum alloys is difficult because of high welding current and small electrical resistance. It is necessary to clarify the relation between the nugget formation and the welding conditions. In this study, the relation between the spot welding conditions and the nugget form was investigated, and the joint strength and the fracture mode were investigated. As a result, the nugget area and micro cracks in the HAZ were increased with increase of the welding current. It is found that in case of aluminum alloys the formation of micro cracks was a main factor of reduction of maximum tensile load of the welded zone.