Fracture Energy in Friction Stir Welding Al6061-T6 by Micro Shear Punch Test

Abstract

Fracture energy was analyzed for FSW (Friction Stir Welding) joint in accordance with the tool rotation speed and feed rate in the thermo-mechanically affected zone. Al6061-T6 sheet with thickness 5mm was welded with 9 conditions (tool rotation speed: 900, 1000, 1100rpm, feed rate: 270, 300, 330mm/min). Tool with shoulder diameter of 18mm and probe diameter of 5mm was used. Specimen size was 10×10×0.5mm. The MSP (Micro Shear Punch) test was carried out to evaluate the load-displacement properties of FSW sheet along the center line of cross section of weldment. The maximum fracture energy was 0.771 J at the tool rotation speed of 1000 RPM and the feed rate of 300 mm/min, which was about 35.9 % of the minimum value. The reason is considered to be that the shape and distribution of precipitates in the weld zone were different and affected the weld strength and ductility.