Friction Stir Welding of Butt Joint between 6063 Aluminum Alloy Rolled Plate and As-cast Mg-Si Aluminum Alloy Plate

Abstract

This paper aims to apply friction stir welding for a butt welded joint between a 6063 aluminum alloy rolled plate and a Mg-Si alloy casted-plate using various parameters such as rotating speeds and travelling speeds. The summarized results are as follows, variation of the rotating and travelling speeds affected to imporve the weld quality. Higher rotating speed and higher travelling speed produced the defects such as holes or uncompleted combination of metals in the weld metal that decreased directly the joint tensile strength. When the sound weld metal that implied the high tensile strength was produced, the failure of the tensile test specimen was located at the aluminum casted-plate. The average tensile strength of the sound joint was about 10-15% higher than that of the tensile strength of the aluminum casted-plate. Microstructure investigation of the optimum welding parameter specimen revealed that the combination of those aluminum alloy plates was completed without any defect in the weld metal. Compressed force occurring by the welding tool produced the small compacted grain in the weld metal and the small combined area band at the interface of the aluminum plate and the weld metal.