Research progress on friction stir welding of aluminum alloy T-joints

Aluminum alloy is diffusely used in aerospace,automobile,marine and chemical industries,and as an important connection form of aluminum alloy thin plate structure assembly,the requirement of welding quality is also gradually improved. A series of problems such as stress concentration,large residual deformation after welding and porosity will be caused by traditional fusion welding method. The traditional friction stir welding has the advantages of less heat production,no need to open the groove before welding,and small residual deformation after welding,which solves this technical difficulty very well. However,the traditional friction stir welding will generate a large amount of flashes and arc defects after welding. As a new friction stir welding technology,stationary shoulder friction stir welding technology has great advantages in the welding of aluminum alloy T-joints. The welding features of aluminum alloy T-joints and the research progress of traditional friction stir welding and stationary shoulder friction stir welding in T-joints are summarized in the present paper. Furthermore,the prospect of the application of friction stir welding technology in T-joint is prospected.