中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 33 No. 6 June 2023 |
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. Light Alloy Research Institute, Central South University, Changsha 410083, China;
4. National Key Laboratory of Science and Technology for National Defence on High-strength Lightweight Structural Materials, Central South University, Changsha 410083, China）
Abstract:An Al-Mg-Sc-Zr alloy rolled sheet was subjected to friction stir welding (FSW) with a tool rotation speed of 500 r/min and a tool travel speed of 100 mm/min. The microstructure of the alloy sheet after FSW was characterized by OM, EBSD and TEM. The microhardness and strength were also tested. The results show that after the FSW, the fiber grains adjacent to the rotating tool are bent. The texture of the rolled sheet is gradually alleviated. In the nugget zone, the size of the tiny equiaxed grains is only 2.31 μm. Al3(Sc,Zr) particles are also affected by the FSW. The distribution and the size of the particles after the FSW are different from those of the original sheet. Moreover, the shape of the Al3(Sc,Zr) particles turns from spherical to polygonal and many particles become incoherent with the Al matrix. The tensile strength of the FSW sheet is 367 MPa and the yield strength is 263 MPa, and those of the original sheet are 414 and 311 MPa.
Key words: Al-Mg-Sc-Zr alloy; friction stir welding; dynamic recrystallization; Al3(Sc,Zr) particles; strength
