研究了7050铝合金双级双峰时效的第二级时效时沉淀相的析出过程及作用。结果表明：合金在第二级时效的硬化第一峰主要由细小、均匀的GP区贡献，而第二峰由晶内细小的η’相与粗大GP区共同作用，后者的强化效果要优于前者的；第二峰峰值时析出的η’相细小均匀地分布于晶内，间距非常小，体积分数较大，GP区粗大；随着时效进一步深入，晶界上的η’相开始聚集粗化，开始转变为平稳的η相，GP区消失。%The precipitation process and effect of precipitated phases at second-stage aging of 7050 aluminum alloy two-stage double peak aging were studied. The results show that the first-peak of alloy second-stage aging was hardened mainly by fine and uniform GP zone and the second-peak was hardened by fine intragranular η′ phases and bulky GP zone, the strengthening effect of the latter was better than the former. The η′ phases which precipitated at peak value of second-stage peak distributed in intragranular uniformly, and η′ phases had very small spacing and large volume fraction, the GP zone was bulky. The η′ phases started to gather and coarsen then change to steady η phases with aging going along further, the GP zone disppeared.
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