中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 8 August 2011 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Northeast Light Alloy Co. Ltd., Harbin 150060, China;
3. School of Physics Science and Technology, Central South University, Changsha 410083, China;）
Abstract:In order to study the welding process, microstructure and properties of Al-Mg-Mn-Sc-Zr alloy, comparative methods of friction stir welding (FSW) and tungsten inert gas (TIG) were applied to the two conditions of this alloy, namely hot rolled plate and cold rolled-annealed plate. The relationships between microstructures and properties of the welded joints were investigated by means of optical microscopy and transmission electron microscopy. Compared with the base metal, the strength of FSW and TIG welded joints decreased, and the FSW welding coefficients were higher than the TIG welding coefficients. The loss of substructure strengthening and a very little loss of precipitation strengthening of Al3(Sc, Zr) cause the decreased strength of FSW welded joint. But for the TIG welded joint, the disappearance of both the strain hardening and most precipitation strengthening effect of Al3(Sc, Zr) particles contributed to its softening. At the same time, the grains in weld nugget zone of FSW welded joints were finer than those in the molten zone of TIG welded joints.
Key words: Al-Mg-Mn-Sc-Zr; friction stir welding; tungsten inert gas; welded joints
