天津大学学报（英文版）
天津大學學報（英文版）
천진대학학보（영문판）
TRANSACTIONS OF TIANJIN UNIVERSITY
2014年
6期
439-443
,共5页
李文亚%李锦锋%张志函%高大路%王卫兵%栾国红
李文亞%李錦鋒%張誌函%高大路%王衛兵%欒國紅
리문아%리금봉%장지함%고대로%왕위병%란국홍
pinless friction stir welding%AA2024-T3%mechanical property%fracture mode
The joining of aluminum alloy sheets with thickness less than 2.0 mm is difficult via conventional friction stir welding owing to the defects in the joint, such as root flaw, keyhole and lazy S. In the present research, a newly designed pinless tool with involute grooves on its shoulder surface was applied to weld 1.5 mm thick AA2024-T3. The effects of the rotating speed and welding speed on the microstructure and mechanical properties of the joints were ana-lyzed. The experimental results showed that the root flaw and keyhole were successfully eliminated. The lazy S was also eliminated under the optimized welding parameters. The maximum tensile strength of the joints was 326 MPa, which is about 74.1% that of the base material. Moreover, all the tensile samples fractured from the retreating side. Two fracture modes were observed during the tensile tests, which are related with the lazy S.
