微量Ag对CP276合金性能和组织的影响

The Effect of Small Additions of Silver on the Tensile Property and Microstructure of Al-Li(CP276)Alloy

研究添加不同含量的Ａｇ对ＣＰ２７６合金的拉伸性能和时效组织的影响。对拉伸强度、延伸率测试及透射电镜观察表明：０．１１ｗｔ％Ａｇ的加入可促进Ｔ_１相析出，使合金强度值升高；０．３８ｗｔ％Ａｇ的加入可在时效前期生成富Ａｇ、Ｍｇ的稳定的ＧＰ区，从而降低合金中Ｃｕ的固溶度，阻碍Ｔ_ｌ相析出，时效后期，ＧＰ区分解，生成大量Ｔ_ｌ相，使合金强度值显著升高。

The effect of change in Ag contents on the tensile property and ageing microstructure of Al-Li (CP 276)alloy has been studied.Adding 0.11wt%Ag to the alloy promote the precipitation of T_1 phase and improve the peak strength.The GP zones containing Ag and Mg appear in the earlier ageing stage in the alloy containing 0.38wt% Ag,decreasing the solubility of Cu in the alloy,preventing the precipitation of T_1 phase and reducing the strength;in the further ageing stage,GP zones are dissolved,T_1 phase precipitated enmously and the peak strength is improved.