Microstructural evolution behavior of aluminum alloy during friction stir welding under different welding and cooling conditions

Dynamic recrystallization (DRX) occurs during friction stir welding (FSW) of Al alloys, but the detailed microstructure evolution have not been elucidated clearly. In this study, the grain evolution mechanism during FSW was investigated with 3 mm thick Al-Mg-Si alloy sheets by the “take-action” technique of FSW. It was found that the FSW of Al alloys included four stages: dynamic recovery, dislocation multiplication, new grain formation and grain growth. we provided the research data including processed data, hardness data, and EBSD data.