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采用搅拌摩擦焊接技术进行了AA7075铝合金的焊接,针对搅拌摩擦焊接试样进行了拉压、弯曲和硬度测量实验,研究了AA7075铝合金在搅拌摩擦焊接过程中的组织演变和力学性能。实验及研究结果表明:焊接的强度高于母材15%,延展性为母材的50%,硬度相对于母材有所下降。在弯曲实验中,搅拌摩擦焊接之后的工件弯曲后更易产生裂缝。AA7075的微观组织演变主要体现在析出物尺寸和分布的变化。实验发现这些热影响区的析出物较为粗糙,而焊接区的析出物较为细小。
The AA7075 aluminum alloy was welded by friction stir welding. The tensile, flexural and hardness measurements of the friction stir welded specimens were carried out. The microstructure evolution and mechanical properties of AA7075 aluminum alloy during friction stir welding were studied. The experimental results show that the welding strength is higher than that of the base metal by 15%, the ductility is 50% of the base metal, and the hardness is lower than that of the base metal. In the bending experiment, the workpiece after the friction stir welding is more prone to cracks. The microstructure evolution of AA7075 is mainly reflected in the changes of precipitation size and distribution. It is found that the precipitates in these heat-affected zones are rough and the precipitates in the weld zone are relatively small.