微量Zn对Al-Cu-Mg合金力学性能及晶间腐蚀的影响

The effect of trace Zn on mechanical properties and intergranular corrosion of Al-Cu-Mg alloys

采用扫描电子显微镜(SEM)、电子背散射衍射(EBSD)、电导率测试及常温拉伸实验,结合剥落腐蚀测试、晶间腐蚀测试和电化学测试研究了微量Zn对Al-Cu-Mg合金组织与性能的影响。试验结果表明,微量Zn的添加明显提高了合金T3态(预拉伸+自然时效)的塑性。随着Zn含量的增加,T3态合金点蚀电位提高,S相、阴极相和铝基体之间的电位差减小,点蚀的形成和晶间腐蚀的传播更加困难,合金的晶间腐蚀敏感性降低。

The effect of trace Zn on the microstructure and properties of Al-Cu-Mg alloys was investigated by scanning electron microscope(SEM),electron backscattered eiffraction(EBSD),electric conductivity test,tensile test,combined with exfoliation corrosion test,intergranular corrosion test and electrochemical test.The test results show that the addition of trace Zn significantly improves the plasticity of the Al-Cu-Mg alloys at T3 conduction.With the increase of Zn content,the pitting potential increases,the potential difference between the S phase,the cathode phase and the aluminum matrix decreases,the formation of pitting corrosion and the propagation of intergranular corrosion are more difficult,and the corrosion resistance of the alloy is improved.