双级固溶处理对7075高强铝合金组织和性能的影响

采用光学显微镜、电子万能试验机、维氏硬度计等对比研究了单级固溶处理与双级固溶处理对7075铝合金显微组织和力学性能的影响。结果表明:相对单级固溶处理,双级固溶处理7075铝合金中第二相粒子可以更为充分的溶入基体,固溶度更高。7075铝合金经460 ℃×1 h+480 ℃×0.5 h双级固溶处理后,组织中第二相粒子体积分数为0.303%,晶粒均匀细小,固溶效果理想。经460 ℃×1 h+480 ℃×0.5 h+120 ℃×24 h固溶时效处理后,7075铝合金硬度、抗拉强度和伸长率分别达到199 HV5、637 MPa和14.1%,综合性能最佳。

Effect of two-stage solution treatment on microstructure and properties of 7075 high strength aluminum alloy

Effects of single-stage and two-stage solution treatment on microstructure and mechanical properties of 7075 aluminum alloy were studied by means of optical microscope,electronic universal testing machine and vickers hardness tester.The results show that the second phase particles of 7075 aluminum alloy treated with two-stage solution are much more dissolved into the matrix and have higher solid solubility than those treated with single-stage solution.After 460℃×1 h+480℃×0.5 h double-stage solution treatment,the volume fraction of the second phase in 7075 aluminum alloy is 0.303%,the grains are uniform and fine,and the solution effect is ideal.The hardness,tensile strength and elongation of 7075 aluminum alloy reach 199 HV5,637 MPa and 14.1%respectively after 460℃×1 h+480℃×0.5 h+120℃×24 h solution and aging treatment,and the comprehensive properties are the best.