The present study appraises the effect of tool rotation direction during dissimilar double-sided friction stir welding of AA6061–AA7075 thick plates. The mechanical strength, fracture behavior and the microstructure evolution for the joints are studied. Sound joints without defect and higher strength was achieved for the joint wherein tool rotation in the second weld is provided in the reverse to that of the first weld. Electron backscatter diffraction of welded joints revealed finer grains at the weld center than observed below the tool shoulder affiliated to high degree of deformation/strain. Pole figures revealed the dominance of high shear texture $B/\overline{B}$ and C components at the weld center. Orientation distribution function revealed the presence of strong intensity recrystallization texture components Cube {001}<100>, Goss {110}<001> and P {011}<112> at the weld center.

本研究评估了在AA6061-AA7075厚板的异种双面摩擦搅拌焊接中刀具旋转方向的影响。研究了接头的机械强度，断裂行为和微观组织演变。对于其中第二焊接中的工具旋转与第一焊接相反的旋转的接头，实现了无缺陷且强度更高的稳固接头​​。焊接接头的电子反向散射衍射显示，在焊接中心处的晶粒比在高度变形/应变所属的刀肩下方观察到的晶粒要细。极点图显示了高剪切质地的优势$乙/\overline{乙}$和C组件位于焊接中心。取向分布函数揭示了在焊接中心存在强强度的再结晶织构成分立方{001} <100>，戈斯{110} <001>和P {011} <112>。