固溶处理对Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd合金组织和力学性能的影响

Effects of solution treatment on microstructures and mechanical properties of Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd aluminum alloy

通过金相显微镜(OM)、扫描电镜(SEM)、示差扫描量热法(DSC)和室温拉伸性能测试等方法,研究固溶处理对新型高强耐热铝合金Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd合金组织和力学性能的影响。结果表明:当固溶温度由510℃升高到525℃时,更多的初生相回溶至基体;当固溶温度继续升至530℃时,初生相则未进一步回溶,而再结晶晶粒的尺寸持续加剧,导致合金软化程度增加;合金的力学性能由时效强化和固溶软化共同影响,该合金优化的固溶处理制度为525℃、2 h,经(525℃,2 h)+(185℃,7 h)峰时效处理后,合金抗拉强度、屈服强度和伸长率分别为608 MPa、587 MPa和10.4%。

The effects of solution treatment on the microstructures and mechanical properties of new high-strength heat-resistant Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd aluminum alloy were studied by OM, SEM, DSC and room temperature tensile test. The results show that, as the solution temperature increases from 510 ℃ to 525 ℃, the primary phases dissolve in matrix. The amount of primary phase has no change with temperature increasing to 530℃. But the size increase of the reerystallized particles gradually leads to the increase of alloy softening. The mechanical properties of aged alloy are determined by precipitation strengthening and solution softening, and the suitable solution treatment for Al-5.8Cu-0.6Mg-0.6Ag-0.3Nd alloy is 525 ℃ for 2 h. After the solution and peak aging of（525 ℃, 2 h）＋（185 ℃, 7 h）, the ultimate tensile strength, yield strength and elongation of the aluminum alloy are 608 MPa, 587 MPa and 10.4%,respectively.