双级时效工艺对Al-5.7Zn-2.2Mg-1.5Cu-0.20Cr合金锻件组织与性能的影响

Effect of two-stage aging process on the microstructure and properties of Al-5.7Zn-2.2Mg-1.5Cu-0.20Cr alloy forgings

借助拉伸试验机、涡流电导仪、透射电镜等研究了双级时效工艺对Al-5.7Zn-2.2Mg-1.5Cu-0.20Cr合金锻件组织性能的影响。结果表明:第一级时效温度对合金锻件的性能影响不大;随第二级时效温度和时间的增加,锻件抗拉强度和屈服强度先增大后减小,电导率明显升高;对锻件进行121℃5 h+163℃20 h双级时效处理后,其力学性能、电导率达到指标要求。

The effect of two-stage aging process on the microstructure and mechanical properties of Al-5.7Zn-2.2Mg-1.5Cu-0.20Cr alloy forgings was studied by means of drawing machine,eddy current conductometer and transmission electron microscope.The results show that the first-stage aging temperature has little effect on the properties of the alloy forgings,while with the increase of the second-stage aging temperature and time,the tensile strength and yield strength of the forgings increase first and then decrease,and the electrical conductivity increases obviously.After 121℃5 h+163℃20 h two-stage aging treatment,the mechanical properties and electrical conductivity of the forgings meet the requirements.