搅拌摩擦加工7055铝合金组织与腐蚀性能研究

Study on the Microstructure and Corrosion Properties of 7055 Aluminum Alloy by Friction Stir Processing

利用搅拌摩擦加工技术搅拌了喷射成形7055铝合金,探讨不同搅拌道次对喷射成形7055铝合金组织和腐蚀性能的影响。结果表明:经搅拌摩擦加工后,7055铝合金组织致密,焊核区形成洋葱纹,面积会随着搅拌道次的增加而增大,晶粒呈现细小等轴晶。固溶处理导致搅拌区晶粒异常长大,异常长大晶粒的面积随着搅拌道次的增加而增大。质量分数3.5%NaCl溶液中的电化学腐蚀表明,随着搅拌道次的增加,合金的自腐蚀电位降低,自腐蚀电流增大,阻抗减小,耐腐蚀性降低。

The effect of different multi-pass friction stir processing on the microstructure and corrosion properties of spray formed 7055 aluminum alloy was studied by using friction stir processing technology.The results show that after friction stirring,the structure of 7055 aluminum alloy is dense,the onion pattern is formed in the weld nugget zone,the zone will increase with the increase of stirring passes,and the grain will show fine equiaxed grains.Solution treatment results in the abnormal growth of the grains in the weld nugget zone,and the zone of abnormal grain growth increases with the increase of stirring passes.The electrochemical corrosion in the 3.5%NaCl solution showed that with the increase of the number of stirring passes,the corrosion resistance of the alloy decreased.With the increase of stirring pass,the self-corrosion potential and impedance of the alloy decrease,but the self-corrosion current increases.And the corrosion resistance of the alloy decreases with the increase of stirring pass.