采用室温拉伸测试，电导率测试，晶间腐蚀及透射电镜等手段研究不同时效制度对7 A 85铝合金显微组织，力学性能以及晶间腐蚀性能的影响。结果表明：合金经过峰时效（120℃／24h ）处理，抗拉强度，伸长率和电导率分别达到760.8M Pa ，8．9％和29．7％ IACS ；合金的主要强化相为GP区，峰时效（T6）合金晶内分布着大量细小而弥散的GP区和少量的η′相。双级时效（120℃／8h＋165℃／12h）时，合金抗拉强度及电导率分别达到597．7M Pa和38．1％ IACS ，且随着时效时间的延长，晶间析出相长大粗化，PFZ带宽化，晶间腐蚀敏感性降低。因此，采用120℃／8h＋165／12h双级时效可以获得较好的综合性能。
T he influence of heat treatment on microstructure ,mechanical properties and intergranular corrosion(IGC) of 7A85 aluminum alloy was investigated by tensile testing ,conductivity testing ,in‐tergranular corrosion testing and transmission electron microscope . The results show that tensile strength ,elongation and conductivity of 7A85 aluminium alloy aged at 120℃ /24h are 760 .8M Pa , 8.9% and 29 .7% IACS respectively ;the main strengthening precipitates in the alloy are GP zones . While the tensile strength and the conductivity of 7A85 aluminium alloy reach 597 .7M Pa and 38 .1%IACS respectively ,after duplex aging at 120℃ /8h+165℃/12h ,and with increase of aging time ,the precipitates in the matrix become coarser and PFZs become broaden ,resulting in the susceptibility to IGC decreasing .Therefore ,the alloy after duplex aging at 120℃/8h+165℃/12h shows good compre‐hensive performance .
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