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采用力学性能试验与透射电镜分析相结合的方法，探讨了７１７５铝合金在长期时效过程中力学性能及微观组织变化的特征。结果表明，合金的硬度及强度存在两个峰值，尽管两个时效峰强度相差不大，但对应第二时效峰后（１４０℃）材料的应力腐蚀敏感性较低。对应第一峰时效后基体组织中存在高密度ＧＰ区；而对应第二峰时效后基体组织中除ＧＰ区外还存在η＇相（ＭｇＺｎ_２）
The mechanical properties and microstructure changes of 7175 aluminum alloy during the long-term aging process were discussed by the combination of mechanical property test and transmission electron microscope analysis. The results show that there are two peaks in the hardness and strength of the alloy. Although the difference between the two aging peaks is not significant, the stress corrosion sensitivity of the alloy after the second aging peak (140 ℃) is low. Corresponding to the first peak after aging in the presence of high-density GP area matrix; and corresponding to the second peak aging in the matrix organization in addition GP area there is still η ’phase (MgZn_2)