Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7952122 | Journal of Materials Science & Technology | 2018 | 9 Pages |
Abstract
In this study, the effects of main welding parameters (rotation speed (Ï) and welding speed (v)) on the microstructure, micro-hardness distribution and tensile properties of friction stir welded (FSW) 2195-T8 Al-Li alloy were investigated. The effects of T6 post-treatments at different solution and aging conditions on the mechanical properties and microstructure characteristics of the FSW joints were also investigated. The results show that with increasing Ï and v, both strength and elongation of the joints increase first, and then decrease with further increase of Ï and v. All the joints under varied welding parameters show significant strength loss, and the strength reaches only 65% of the base metal. The effect of T6 post-heat treatment on the mechanical properties of the joints depends on the solution and aging conditions. Two heat treatment processes (480 °C Ã 0.5 h quenching + 180 °C Ã 12 h, 520 °C Ã 0.5 h quenching + 180 °C Ã 12 h aging) are found to increase the joint strength. Furthermore, low temperature quenching (480 °C) is more beneficial to the joint strength. The joint strength can reach 85% of the base metal. Whereas both low temperature aging (140 °C Ã 56 h) and stepped aging (100 °C Ã 12 h + 180 °C Ã 3 h) processes decrease the joint strength. After heat treatment all the joints show decreased ductility due to the obvious grain coarsening in the nugget zone (NZ) and thermo-mechanically affected zone (TMAZ).
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Chemistry
Authors
J. Zhang, X.S. Feng, J.S. Gao, H. Huang, Z.Q. Ma, L.J. Guo,