作　　者： ; ; ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院

出　　处： 《中南大学学报（自然科学版）》 2007年第4期617-622,共6页

摘　　要： 采用恒温浸泡方法、极化曲线测量、金相和透射电镜技术研究不同时效温度和不同时效时间处理7A52铝合金的晶间腐蚀和剥落腐蚀行为。研究结果表明:7A52铝合金的晶间腐蚀和剥落腐蚀敏感性随着时效温度的升高和时效时间的增加而减小;腐蚀敏感性随着时效温度的变化由大到小的顺序为:自然时效,100℃/24 h(欠时效),120℃/24 h(峰时效),150℃/24 h(过时效);在120℃时效条件下,腐蚀敏感性随时效时间的变化由大到小的顺序为:120℃/16 h(欠时效),120℃/24 h(峰时效),120℃/60 h(过时效);合金的腐蚀敏感性与晶界析出相(MgZn2)和无沉淀析出带(PFZ)的特征有关;晶界析出相呈链状分布时合金腐蚀敏感性大,晶界析出相尺寸越大,分布越不连续,PFZ越宽,合金腐蚀敏感性越小。 The intercrystalline corrosion and exfoliation corrosion properties of 7A52 aluminum alloy were investigated at different aging temperatures and time using constant temperature immersion corrosion method, polarization curve measure, optical microscopy and transmission electron microscopy. The results show that intercrystalline corrosion and exfoliation corrosion sensibility of 7A52 aluminum alloy decrease gradually with the increase of aging temperature and time. Corrosion sensibility order from high to low at different aging temperature is as follows： nature aging, 100 ℃/24 h（under aging）, 120 ℃/24 h（peak aging）, 150 ℃/24 h（over aging）. Aging at 120 ℃, corrosion sensibility order from high to low is as follows： 120 ℃/16 h （under aging）, 120 ℃/24 h（peak aging）, 120 ℃/60 h（over aging）. Corrosion sensibility of alloy is related to the characteristics of equilibrium .phases （MgZn2） and precipitated free zone （PFZ） at grain boundaries. When grain-boundary equilibrium phases have reticulate or chain distribution, the corrosion sensibility of alloy is high. On the contrary, with the equilibrium phases discontinuous and PFZ widening, the corrosion sensibility of alloy decreases.

关 键 词： 铝合金 时效 晶间腐蚀 剥落腐蚀 极化曲线

领　　域： [金属学及工艺] [金属学及工艺]