中文摘要：

通过固溶-时效处理及显微组织分析，研究了微量Ag对Al—5．3Cu—0．8Mg合金组织与时效行为的影响。结果表明，Ag的加入改变了合金的时效过程，Ag与Mg的强烈作用能够抑制合金GP区的析出，促进片状强化相Q的析出；随着Ag含量的增加，析出强化相Q的时间明显缩短，达到时效峰值的时间也明显减少；不同含Ag量的Al—5．3Cu-0．8Mg合金的硬度都随时效时间的延长先增加后减小，Al—5．3Cu—0．8Mg-0．45Ag达到Hv172时效峰值的时间为9h，Al-5．3Cu-0．8Mg—0．6Ag合金达到Hv165时效峰值的时间为6h；随着Ag含量的增加，Al—5．3Cu-0．8Mg合金铸态组织的硬度增加，当Ag含量达到0．6％时，硬度达到峰值。

英文摘要：

By the solution-aging treatment and microstructure analysis, the alloying effect of trace Ag on the microstructure and aging behavior of Al-5.3Cu-0.8Mg alloy was investigated. The results show that the addition of Ag have an effect on the aging process, the strong interaction of Mg and Ag will restrain the precipitation of GP zone and promote the precipita- tion of flake strengthening phase Ω. With an increase of Ag, the decrease of precipitation time of strengthening phase Ω is obviously and the same to aging time for reaching to the hardness peak. The peak aging time of Al-5.3Cu-0.8Mg-0.4SAg alloy is 9 h and that of Al- 5.3Cu-0.8Mg-0.6Ag alloy is 6 h. The hardness values of Al-5.3Cu-0.8Mg alloy with differ- ent Ag both increases first and then decreases as prolonging the aging time. The hardnegs of as-cast microstructure of Al-5.3Cu-0.8Mg alloy increases with the increase of Ag, when the amount of Ag in the alloy is 0.6 %, the hardness value is the highest, and then the increase of the Ag content has little effect to hardness.