固溶时间对7050铝合金组织和性能的影响

采用金相组织观察（OM）、常温拉伸试验以及扫描电镜（SEM）等研究了固溶保温时间对7050铝合金固溶程度、微观组织及力学性能的影响.结果表明：随着固溶时间的增加，合金组织的回复再结晶程度增大，变形晶粒转变为等轴晶粒.7050铝合金中的难溶相Al7Cu2Fe和Al2CuMg随着固溶时间的延长仍然难以溶解；7050铝合金较理想固溶处理制度为477 ℃固溶1 h，经过121 ℃时效24 h后合金的力学性能最佳，Rm = 605 MPa、Rp0.2 = 547 MPa、A = 12.8%.
The effect of solution time on the solid solution degree， microstructure and mechanical properties of 7050 aluminum alloy was studied by optical microscopy（OM），tensile test at room temperature and scanning electron microscopy（SEM）.The results show that，with the increase of solution time，the degree of recovery and recrystallization increases and the deformation grains change into equiaxed grains.The insoluble phases of Al7Cu2Fe and Al2CuMg in 7050 aluminum alloy are still difficult to dissolve with the prolongation of the solution time. The optimum solution process of 7050 aluminum alloy is solution at 477 ℃ for 1 h. After aging at 121 ℃ for 24 h，the best mechanical properties are measured，in which the tensile strength is 605 MPa，yield strength is 547 MPa，and elongation is 12.8%.