Comparative study on fatigue properties of friction stir and MIG-pulse welded joints in
5083 Al-Mg alloy
5083 Al-Mg alloy
(1. School of Materials Science and Engineering, Tianjin University,
Tianjin 300072, China;
2. China Friction Stir Welding Center Beijing Friction Stir Welding Technology Limited Company, Beijing 100024, China)
Tianjin 300072, China;
2. China Friction Stir Welding Center Beijing Friction Stir Welding Technology Limited Company, Beijing 100024, China)
Abstract: The objective of this investigation was to compare the fatigue properties of friction stir welds with those of MIG-pulse welds. The 5083 Al-Mg alloy was welded by single pass friction stir welding(FSW) and double-sided MIG-pulse welding. The results show that friction stir(FS) welds have a better appearance than MIG-pulse welds for the lack of voids, cracks and distortions. Compared with the parent plate, FSW welds exhibit similar fine grains, while MIG-pulse welds display a different cast microstructure due to the high heat input and the addition of welding wire. The S—N curves of FSW and MIG-pulse joints show that the fatigue life of FS welds is 18-26 times longer than that of MIG-pulse welds under the stress ratio of 0.1 and the calculated fatigue characteristic values of each weld increase from 38.67MPa for MIG-pulse welds to 53.59MPa for FSW welds.
Key words: friction stir welding; MIG-pulse welds; fatigue properties; microstructures