作　　者： ; ; ;

机构地区： 南京航空航天大学材料科学与技术学院

出　　处： 《南京大学学报（自然科学版）》 2009年第2期162-166,共5页

摘　　要： 采用透射电子显微镜和拉伸实验研究了不同热暴露条件下7050-T7651铝合金微观组织和拉伸力学性能.结果表明:未经热暴露的7050-T7651铝合金中主要析出相为Guinierprestonzone(GP区)和η′相,其中η′相与基体的取向关系为[0001]η′//[11]Al,(100)η′//(110)Al.随后7050-T7651铝合金在不同温度下分别热暴露500h,随着热暴露温度的提高,合金中析出相长大越明显,晶界附近无沉淀析出带(PFZ)宽化也越明显;热暴露温度提高,合金强度下降越多.7050-T7651铝合金经过长时间热暴露后强度下降、塑性提高的主要原因是晶内主要强化相GP区和η′相的长大粗化以及晶界附近无沉淀析出带(PFZ)宽化. The microstructures and tensile properties at different thermal exposure conditions of 7050--T7651 alu- minum alloy were studied by the means of transmission electron microscopy （TEM） and tensile test. Guinier preston （GP） zone and η′ phase were the main precipitates in original 7050--T7651 aluminum alloy. The orientation rela tionship between η′ and matrix is [0001]η′//[11]Al,（100）η′//（110）Al. The precipitates became coarser; the breadth of precipitate free-zones （PFZ） became wider when the 7050--T7651 aluminum alloy was exposed at higher thermal temperature for 500 hours. The higher temperature the alloy was exposed at, the more seriously strength decreased. GP zones and η′ recipitates getting coarser and the PFZ getting wider both should be responsi ble for the strength decline and elongation rise of the 7050--T7651 alloy during thermal exposure.

关 键 词： 铝合金 热暴露 微观结构

领　　域： [政治法律] [政治法律] [理学] [理学]