A phase field study for influence of elastic energy on L1_0→L1_2 transient ordering in Ni_(75)Al_(17)Zn_8  

作　　者：ZHAO Yan CHEN Zheng WANG YongXin ZHANG MingYi ZHANG Jing 

机构地区：[1]Department of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China [2]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China

出　　处：《Chinese Science Bulletin》2010年第26期3044-3050,共7页

基　　金：supported by the National Natural Science Foundation of China (50671084 and 50875217)

摘　　要：The influence of the elastic energy on L10→L12 transient ordering transformation was investigated by microscopic phase field method. It is found that there are three stages experienced in atomic ordering: solute clustering+L10 short range ordering → L10 long range ordering → L12 long range ordering. Before the formation of the high ordered L12 phase, it has firstly taken place the transformation from matrix to L10 phase, and then held the L10→L12 secondary transformation. Elastic energy is proved to take little effect on the stage of short range ordering, but as the elastic energy is multiplied, it obviously shortened the course of the solute clustering, and speeded up the proceeding of the L10 long range ordering transition. Accordingly, the increased elastic energy also strengthens the single crystalline directionality of L10 phase projecting on 2D plane and makes the ordered degree of Al and Zn atoms enhanced. With the temperature elevation, Al's and Zn's ordered degree decreased in L10 phase.The influence of the elastic energy on L10→L12 transient ordering transformation was investigated by microscopic phase field method. It is found that there are three stages experienced in atomic ordering： solute clustering＋L10 short range ordering → L10 long range ordering → L12 long range ordering. Before the formation of the high ordered L12 phase, it has firstly taken place the transformation from matrix to L10 phase, and then held the L10→L12 secondary transformation. Elastic energy is proved to take little effect on the stage of short range ordering, but as the elastic energy is multiplied, it obviously shortened the course of the solute clustering, and speeded up the proceeding of the Llo long range ordering transition. Accordingly, the increased elastic energy also strengthens the single crystalline directionality of Llo phase projecting on 2D plane and makes the ordered degree of Al and Zn atoms enhanced. With the temperature elevation, Al＇s and Zn＇s ordered degree decreased in Llo phase.

关 键 词：原子排列 弹性能 能量 2型 瞬态 短程有序 长程有序 平面投影 

分 类 号：O753.3[理学—晶体学] TB33[一般工业技术—材料科学与工程]