Orientation-dependent morphological stability of grain boundary groove  

作　　者：王理林 林鑫 王志军 黄卫东 

机构地区：[1]School of Mechanical Engineering, Northwestern Polytechnical University [2]State Key Laboratory of Solidification Processing, Northwestern Polytechnical University

出　　处：《Chinese Physics B》2014年第12期293-297,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.51271213);the National Basic Research Program of China(Grant No.2011CB610402);China Postdoctoral Science Foundation(Grant No.2013M542384);the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20116102110016)

摘　　要：Crystal orientation influences the morphological stability of solid–liquid interface during directional solidification of alloy, resulting in the variation of solidified microstructure. In this paper, the morphological evolution near grain boundary grooves（GBGs） with different crystal orientations in a dilute succinonitrile alloy under low temperature gradient and interface velocity is observed in situ. Under experimental conditions, the macroscopic solid–liquid interface is planar and keeps stable, while in GBGs there emerge protrusion and undulation. It is found that the morphological stability of GBG is dependent on crystal orientation. Specifically, for succinonitrile with a body-centered cubic crystal structure, GBGs around the 100 crystal orientation keep stable, while those apart from the 100 crystal orientation become unstable under the same conditions. So it is concluded that 100 crystal orientation favors the morphological stability of GBG.Crystal orientation influences the morphological stability of solid–liquid interface during directional solidification of alloy, resulting in the variation of solidified microstructure. In this paper, the morphological evolution near grain boundary grooves（GBGs） with different crystal orientations in a dilute succinonitrile alloy under low temperature gradient and interface velocity is observed in situ. Under experimental conditions, the macroscopic solid–liquid interface is planar and keeps stable, while in GBGs there emerge protrusion and undulation. It is found that the morphological stability of GBG is dependent on crystal orientation. Specifically, for succinonitrile with a body-centered cubic crystal structure, GBGs around the 100 crystal orientation keep stable, while those apart from the 100 crystal orientation become unstable under the same conditions. So it is concluded that 100 crystal orientation favors the morphological stability of GBG.

关 键 词：morphological instability grain boundaries crystal orientation SOLIDIFICATION 

分 类 号：O76[理学—晶体学]