(1.中南大学材料科学与工程学院，长沙410083；
2. 中南大学有色金属材料科学与工程教育部重点实验室，长沙410083)
摘 要: 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%。
关键字: Al-Cu-Mg-Ag-Nd合金；固溶处理；显微组织；力学性能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract: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 to530 ℃.But the size increase of the recrystallized 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 is525 ℃ 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 alloyare 608 MPa,587 MPa and 10.4%, respectively.
Key words: Al-Cu-Mg-Ag-Nd alloy; solution treatment; microstructure; mechanical property
