为了获得2A12铝合金搅拌摩擦焊(FSW)焊接过程中焊接温度场的动态演变和焊接热循环曲线的变化规律,探索焊接热作用过程与接头微观组织的内在联系,利用ANSYS软件,建立了搅拌摩擦焊接传热过程的有限元数值分析模型,对6 mm厚2A12铝合金FSW焊接过程进行了数值分析,观察了焊核区、 热力影响区、 热影响区和母材的显微组织,分析了接头不同区域所经历的热作用和机械作用.结果表明,焊核区实质为焊接过程中温度超过了母材实际再结晶温度的区域;焊核区上部、 焊核区下部、 热力影响区、 热影响区的显微组织特征与各自所经历的热-力复合作用具有密切的内在联系.%In order to get temperature filed dynamic evolution and the change rule of welding thermal cycle curve of 2A12 aluminum alloy during friction stir welding(FSW) process, explore the inner link between welding thermal effect and welded joint microstructure, a finite element numerical analysis model of FSW heat transfer process was established by using ANSYS. It carried out numerical analysis for 6 mm thickness 2A12 aluminum alloy FSW process, the microstructures in weld nugget zone (WNZ), thermo-mechanical affected zone (TMAZ), heat affected zone (HAZ) and base metal were observed, and the thermal effect and mechanical effect in different zones of welded joint were analyzed. The results showed that the weld nugget zone is the region within which the temperature during welding is higher than the re-crystallization temperature of the base metal, and the microstructure features of the upper and lower part of WNZ, TMAZ, and HAZ are related to different thermal and mechanical combined actions which have been experienced in the welding process.
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