DONG Fengbo, FENG Xiaosong, LUO Chuanhong, et al. Analysis on microstructure and mechanism of high temperature oscillation heat treatment after friction stir welding[J]. 2020,50(6):26-29.
DONG Fengbo, FENG Xiaosong, LUO Chuanhong, et al. Analysis on microstructure and mechanism of high temperature oscillation heat treatment after friction stir welding[J]. 2020,50(6):26-29. DOI: 10.7512/j.issn.1001-2303.2020.06.04.
Friction stir welding(FSW) was used to weld 2219-O aluminium alloy. The welded joints were treated by high temperature oscillating solid solution heat treatment. The mechanism of abnormal grain growth of FSW joints was studied by analyzing the microstructures before and after heat trea-tment,and the corresponding restraining measures were put forward. The results show that the thermal stability of the weld formed by FSW is poor,the grain is easy to reheat and grow,and the grain size after conventional heat treatment reaches millimeter level. High temperature oscillating solid solution heat treatment around the lower limit of solution temperature can effectively restrain the formation of coarse grains. When the temperature oscillation amplitude is greater than 90 ℃,the grain size of the nugget is about 20 μm in diameter.
关键词
搅拌摩擦焊微观组织高温振荡热不稳定性
Keywords
FSWmicrostructurehigh temperature oscillationthermal instability