The AZ31 and AM60 alloys were used for dissimilar friction stir welding (FSW) in this study. The microstructure characteristics of the joint and its three-point bending performance were investigated. The electron backscattered diffraction results showed that the grains in the nugget zone (NZ) were more uniform and refined to a certain extent after FSW, but the grain size of AM60 in the NZ was larger than that of AZ31. The texture was strong locally in the NZ and presented a symmetric distribution characteristic from the advancing side to the retreating side. There were special texture features in the joint, resulting in the occurrence of severe strain localization during the bending process compared with the base materials, which can be well explained by the calculated Schmid factor in terms of the assumed stress state for bending. The bending tests revealed that the joint presented good bending properties compared with AZ31 BM. The bending fracture morphologies suggested that the fracture tended to the NZ interface on the AZ31 side, which was mainly due to the higher SF for basal slip and dislocation concentration degree in the region, and the relatively lower bending strength of AZ31 metal.

在本研究中，AZ31 和 AM60 合金用于异种搅拌摩擦焊 (FSW)。研究了接头的显微组织特征及其三点弯曲性能。电子背散射衍射结果表明，FSW后熔核区（NZ）的晶粒更加均匀和细化到一定程度，但NZ中AM60的晶粒尺寸大于AZ31。新西兰局部纹理强烈，呈现出从前进侧到后退侧的对称分布特征。接头处存在特殊的纹理特征，导致在弯曲过程中与母材相比出现严重的应变局部化，这可以通过计算的 Schmid 因子根据弯曲的假定应力状态很好地解释。弯曲试验表明，与 AZ31 BM 相比，该接头具有良好的弯曲性能。弯曲断口形貌表明，断裂趋向于AZ31侧的NZ界面，这主要是由于该区域的基底滑移和位错集中度较高，而AZ31金属的弯曲强度相对较低。