Cu含量对7xxx系铝合金力学性能及腐蚀性能的影响

Effects of Cu Content on Mechanical Properties and CorrosionProperties of 7xxx Series Aluminum Alloys

文章以添加不同Cu含量(wt.%)(1.4%~2.6%)的Al-Zn-Mg-xCu-Ce-Zr合金为研究对象,通过OM、TEM以及室温拉伸、剥落腐蚀、电化学腐蚀等实验,研究Cu元素对铝合金组织及性能的影响规律。结果表明,随着Cu含量的增加,合金晶内析出相的平均尺寸先减小后增大,合金的力学性能呈先升高后降低的趋势,抗腐蚀性能逐渐降低。当Cu含量为2.2%时,合金晶内析出相的平均尺寸最小且表现出最高的力学性能;当Cu含量为1.4%时,合金表现出最佳的综合性能,抗拉强度、屈服强度和延伸率分别为682MPa、605MPa和13.8%;腐蚀电流密度为1.496×10^(-5) A/cm^(2)。

In this paper,the effects of Cu on the microstructure and properties of Al-Zn-Mg-xCu-Ce-Zr alloys with different Cu contents(1.4%~2.6%,wt.%)are studied by OM,TEM,room temperature tensile,spalling corrosion and electrochemical corrosion tests.The results show that with the increase of Cu content,the average size of the precipitated phase in the alloy decreases first and then increases,the mechanical properties of the alloy increase first and then decrease,and the corrosion resistance decreases gradually.When the Cu content is 2.2%,the average size of precipitated phase is the smallest and the mechanical properties are the highest.When Cu content is 1.4%,the alloy exhibits the best comprehensive properties;the tensile strength,yield strength and elongation are 682MPa,605MPa and 13.8%,respectively.The corrosion current density is 1.496×10^(-5) A/cm^(2).