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： 《南京航空航天大学学报》 2007年第1期133-136,共4页

摘　　要： 采用透射电子显微镜对固溶单级时效处理7055铝合金中的沉淀相进行了研究。在时效1 h内,Guinier-Preston(G-P)区即在{111}面上形成并具有片状结构,随着时效时间增加,G-P区逐渐长大。η′亚稳相也在G-P区形成不久即析出,它们是具有沿{110}方向,呈成分调制的结构。G-P区和η′相的析出是铝合金在时效过程中强度和硬度迅速上升并达到峰值的主要原因。在时效达到4 h时,η相便析出,它们与基体存在[1-10]η//[110]Al,(001)η//(111)Al的取向关系。G-P区含量减少和η相长大引起铝合金强度和硬度的降低。 Transmission electron microscopy （TEM） study of microstructural development of a 7055 （Al Zn Mg Cu）alloy is conducted during the process of single-ageing, it can be observed that Guinier Preston（G-P） zones are formed on {111} planes to have the platelike structure when sample is aged for 1 h. They grow up gradually with the increasing ageing time. η′ phase appears after G-P zones are formed. It is along {110} direction and takes on the structure of composition modulation. It is the precipitation of G-P zones and η phase, making the strength and hardness of 7055 Al alloy increase and reach the peak value during the process of ageing, η phase starts to occur after 4 h ageing and have an orientation rela- tionship with matrix [i10]η//[110]Al,（001）η//（111）Al. With the further ageing, the number of G- Pzones decreases and η′ phase increases, the strength and the hardness of 7055 Al alloy decrease.

关 键 词： 铝合金 时效 透射电子显微术 显微结构

领　　域： [金属学及工艺] [金属学及工艺]