摘要
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 microstructures of 7175 aluminium alloy with long aging have been investigate. The results indicate that the hardness and strength of 7175 aluminium alloy have double peaks. Although the intensity of double peaks is almost equal, the stress corrosion susceptibility of the alloy 2nd peakaged is lower than that of the first peak aged. The microstructure of the alloy first peak aged is high density GP zones ,whereas the microstructure of the alloy second peak aged is GP zones and η' phase.
关键词
铝合金
时效
力学性能
应力腐蚀
敏感性
aluminium alloy, aging, mechanical property,stress corrosion susceptibility, microstructure