中文摘要：

采用光学金相、扫描电镜、室温拉伸、显微硬度、导电率和晶间腐蚀试验，研究逐步固溶对7050铝合金组织、力学性能和晶间腐蚀性能的影响。结果表明：逐步强化固溶（400℃×4h＋478℃×lh）＋HLA10（190℃×10min＋120℃×24h）较常规固溶（478℃×1h）＋HLA20（190℃×l0min＋120℃×24h），显著减小合金再结晶数量和晶粒尺寸：EDS分析未溶的第二相为AI7Cu2Fe和AI2℃uMg相；合金的抗拉强度由530．6MPa提高到569．1MPa，伸长率提高了14％，电导率、硬度数值较高；抗晶间腐蚀等级由3级提高至2级。

英文摘要：

The microstructure, mechanical properties of 7050 A1 alloy treated with step-solution were studied by OM, SEM, tensile test, microhardness, conductivity and intergranular corrosion experiments. The results show that compared with the conventional solid-solution （478 ℃× 1 h） and HLA10（190 ℃×10min＋120 ℃×24h） treatment, the step-solution （400 ℃× 4 h＋478 ℃× 1 h） and HLA10（190 ℃×l0min＋120 ℃×24h） reduces the number of recrystallization and grains. The undissolved second phases analyzed by EDS are A17Cu2Fe and A12CuMg. Its strength increases from 530.6 MPa to 569.1 MPa, elongation enhances by 14%, its hardness and conductivity are relatively high. The intergranular corrosion resistance advances froms the third to the second grade.