Martensitic transformation, twin boundary and phase interface mobility of directionally solidified Ni-Mn-Ga alloys during compression by EBSD tracing

18th International Conference on Textures of Materials

材料科学;物理学

Dai, Yanchao^1 ; Hou, Long^1 ; Fautrelle, Yves^2 ; Li, Zongbin^3 ; Esling, Claude^4 ; Ren, Zhongming^1 ; Li, Xi^1,2

State Key Laboratory of Advanced Special Steels, Shanghai University, Shanghai

200072, China^1

EPM-Madylam, ENSHMG, BP 38402, StMartin d'Heres, cedex, France^2

Key Laboratory for Anisotropy and Texture of Materials, Northeastern University, Shenyang

110819, China^3

Laboratoire d'Ètude des Microstructures et de Mécanique des Matériaux (LEM3), CNRS UMR 7239, Université de Lorraine, Metz

57045, France^4

关键词: Directionally solidified;    Dislocation mobility;    Electron back scatter diffraction;    Interdendritic regions;    Martensitic transformation temperatures;    Preferred orientations;    Stress induced martensitic transformation;    Uni-axial compression;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/375/1/012023/pdf
DOI  :  10.1088/1757-899X/375/1/012023

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Directionally solidified Ni-Mn-Ga alloy with orderly arrayed austenite and non-modulated martensite (NM) was formed due to microsegregation between dendrite arm and interdendritic region, leading to preferred orientation of Aand Mcoexistence at ambient temperature. The stress-induced martensitic transformation took place due to the increase of martensitic transformation temperature under step-wise uniaxial compression. The detwinning process accompanied with dislocation mobility was easy to carry out on the twin planes 45° inclined to the compression axis, compared with the twin planes parallel to the compression axis in the dominant twinned groups. The martensitic transformation and reorientation of variants were investigated by electron backscatter diffraction.