为了提高Q235钢板和6082－T6铝合金对接的连接强度，采用搅拌摩擦焊进行对接焊接．研究了不同尺寸和形状的搅拌头、转速、焊接速度和偏移量等对铝钢对接焊缝组织的影响，进而优化了搅拌摩擦焊工艺．实验结果表明：不同形状的搅拌头影响接头“钉子”形状，接头的不同位置处由于受到不同热循环和搅拌导致晶粒尺寸不同，从而影响接头的力学性能．当搅拌针旋转速度260 r／min，焊接速度16 mm／min，针头偏向铝侧0．2 mm 时，所得焊缝的拉伸强度为141．204 MPa，为最佳工艺参数．在此最优参数下获得过渡层的厚度约为8μm，界面的主要成分是FeAl3．%Friction stir butt welding was employed to improve the joining strength between Q235 steel plate and 6082-T6 aluminum alloy. The welding process was optimized by investigating the effects of various parameters on the welding quality, such as size and shape of the stir⁃welding head, rotational speed, welding speed, and the offset distance. The results showed that the shape and dimension of stir⁃welding head had decisive impact on“naill” profile of the joint. The grain size varied across the joint due to non⁃uniform thermal field during the process resulting in different mechanical properties. After optimization, the tensile strength of the weld could achieve 141.204 MPa and the aluminum⁃steel transmission layer was about 8μm which mainly consisted of FeAl3 intermetallics. The optimum process parameters were as follows:rotation speed is 260 rpm, welding speed 16 mm/min and the pin was 0.2 mm towards aluminum alloy side.
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