Innovative Design and Analysis of Friction Stir Welding

Friction stir welding has been extensively studied and widely used in various industries. However, there are still many areas to be improved. In this study, vertical eccentric friction stir welding from previous research is used to preform friction stir welding on Al 7075. In the previous research, a novel eccentric friction stir pin was designed in order to eliminate the need of the tilt angle during welding of 4.8-mm thick AA6061-T6 plates. The design parameters included: eccentricity, tapering, and screw design. Welds free of defects were successfully produced using a specially designed pin with eccentric, tapered and screwed design characteristics. In this study, aluminum 7075 with plate thickness of 8.0 mm were used to produce friction stir welds. Various PWHT and shot peening were introduced to the friction stir weld and tensile tests and corrosion tests were also carried out. In addition, measurement of welding residual stresses using x-ray will be conducted on various locations on the surface. Shot peening was used to modify the residual stress of the plate surfaces. Quantitative control of shot peening parameters becomes possible because of the accurate x-ray measurement. Consequently, effect of shot peening during heat treatment on the corrosion resistance of a friction stir weld is shown to be positive, meanwile the coarsening of the metal in stirring zone during solution heat treatment were found.

Project ID:PB10408-5757
External Project ID:MOST104-2221-E182-066