In this work, a relationship between welding conditions, annealing behavior, and mechanical performance of friction-stir welded (FSWed) 6061-T6 aluminum alloy was examined. In the entire studied FSW range, the welded material was found to be unstable against abnormal grain growth during post-weld solutionizing treatment. However, a lowering of the FSW heat input tended to inhibit this undesirable phenomenon. In addition to the stir zone, the abnormal microstructural coarsening was also observed in the heat-affected zone, whereas the thermo-mechanically affected zone experienced static recrystallization. In all cases, the abnormal grain growth was found to result in ~25-35°<110> rotation of the original crystallographic texture. Hence, this process was suggested to be governed by the orientation-growth mechanism. Due to the relatively high strain-hardening ability intrinsic to the coarse-grained materials, the abnormal grains suppressed tensile strain in the stir zone during transverse tensile tests thus degrading weld ductility.

在这项工作中，研究了搅拌摩擦焊接（FSWed）6061-T6铝合金的焊接条件，退火行为和机械性能之间的关系。在整个研究的FSW范围内，发现焊接后的固溶处理过程中，焊接材料对异常晶粒长大是不稳定的。然而，降低FSW热输入趋向于抑制这种不希望的现象。除了搅拌区，在热影响区也观察到异常的微观组织粗化，而热机械影响区经历了静态重结晶。在所有情况下，发现异常晶粒生长导致原始晶体学织构的〜25-35°<110>旋转。因此，该过程被认为是由取向-生长机制控制的。