【摘要】 将7050铝合金模锻件产品取样进行475℃×1 h固溶处理后，按照105℃×8 h、120℃×8 h、150℃×4 h、177℃×7 h依次叠加时效处理并于中间过程取样，采用透射电镜（TEM）、布氏硬度测试（HB）及能谱分析（EDS）等方法研究7050铝合金模锻件的固溶及四级时效热处理工艺过程中组织、化合物相和力学性能的演变规律。结果表明：固溶态合金中有含Fe、Ni、Ti、Si等杂质元素的未溶化合物以及少量的S相（Al2CuMg）；合金依次经4次时效处理后硬度逐渐升高；时效处理过程中，S相同时沿晶界和晶内析出，η相（MgZn2）呈颗粒状分布于Al基体上，尺寸约为40～50 nm。其中177℃时效处理后观察到的纳米级析出物η或η’相是7050合金的主要强化相。更多还原

【Abstract】 After solution of 475℃×1 h and quenching process for the samples cut from die forged 7050 aluminum alloy product, the aging treatments of 105℃ × 8 h, 120℃ × 8 h, 150℃ × 4 h and 177℃ × 7 h were carried out in sequence to form a multistage aging heat treatment. The transmission electron microscopy(TEM), Brinell hardness test(HB) and energy dispersive spectroscopy(EDS) test were used to investigate the evolution of microstructure, compound phase and mechanical properties during the solid solution and four stage aging heat treatments separately. The results show that there are undissolved compounds containing impurity elements such as Fe,Ni, Ti, Si and a small amount of S phase(Al2 CuMg) in the solid solution alloy. The hardness of the alloy increased gradually after each aging treatment, During aging treatments, S phase precipitates along grain boundary and inside grainsat the same time. TEM investigation shows that the typical η phase(MgZn2) is distributed in the Al matrix in granular form with a size of 40-50 nm.The precipitate ηor η’ phase observed after solution treatment of 475℃×1 h and aging treatment of 177℃×8 h is the main strengthening phase of 7050 alloy.更多还原