热处理对Al-Zn-Mg-Cu合金组织和性能的影响

Effect of Heat Treatment on Structure and Properties of Al-Zn-Mg-Cu Alloy

在7075铝合金的原有成分基础上减少了合金中的Mg含量,提高了Zn/Mg元素比例,并对成分改动后的Al-Zn-MgCu合金进行了不同时间的固溶以及单级时效,以探讨热处理工艺对其显微组织和力学性能的影响。结果表明:固溶工艺为470℃×2 h时,大部分的粗大第二相溶入到基体中,与此同时,合金的强度和塑性均达到较好的水平,抗拉强度、屈服强度和延伸率分别为571.71、415.00 MPa和16.16%。当时效温度为120℃时间为12~28 h时,随着时效时间的延长,合金的强度先升高后降低,塑性呈逐渐下降的后略微升高的趋势。时效强度峰值为24 h时,合金的抗拉强度、屈服强度分别为637.65、579.65 MPa。

In this experiment,to improve Zn / Mg element proportion,the content of Mg in 7075 aluminum alloy has been reduced.Moreover,the Al-Zn-Mg-Cu alloy with different composition was treated by different time solid solution and single-stage aging to explore the influence of heat treatment process on microstructure and mechanical properties. The results show that,when the solution temperature is 470 ℃ × 2 h,most of the coarse phase is dissolved in the matrix. At the same time,the strength and the plasticity of the alloy reach a good level. The tensile strength,yield strength and elongation are 571. 71 MPa,415. 00 MPa and 16. 16%. When the aging temperature is 120 ℃ for 12 ~ 28 h,the strength of the alloy increases first and then decreases,and the plasticity decreases gradually and then increases slightly with the aging time prolonging. The tensile strength and yield strength of the alloy were 637.65 MPa and 579. 65 MPa when the peak strength was 24 h.