Vol.120, No.2, 2019, pp.319-332, doi:10.32604/cmes.2019.06447
OPEN ACCESS
ARTICLE
The Analysis of Thermal-Induced Phase Transformation and Microstructural Evolution in Ni-Ti Based Shape Memory Alloys By Molecular Dynamics
  • Hsin-Yu Chen1, Nien-Ti Tsou1,*
Department of Materials Science and Engineering, National Chiao Tung University, Ta Hsueh Road, Hsinchu 30013, Taiwan.
*Corresponding Author: Nien-Ti Tsou. Email: tsounienti@nctu.edu.tw.
(This article belongs to this Special Issue: Nano/Micro Structures in Application of Computational Mechanics)
Abstract
Shape memory alloys has been widely applied on actuators and medical devices. The transformation temperature and microstructural evolution play two crucial factors and dominate the behavior of shape memory alloys. In order to understand the influence of the composition of the Ni-Ti alloys on the two factors, molecular dynamics was adopted to simulate the temperature-induced phase transformation. The results were post-processed by the martensite variant identification method. The method allows to reveal the detailed microstructural evolution of variants/phases in each case of the composition of Ni-Ti. Many features were found and having good agreement with those reported in the literature, such as the well-known Rank-2 herringbone structures; the X-interface; Ni-rich alloys have lower transformation temperature than Ti-rich alloys. In addition, some new features were also discovered. For example, the Ti-rich alloys enabled an easier martensitic transformation; the nucleated martensite pattern determined the microstructural evolution path, which also changed the atomic volume and temperature curves. The results generated in the current study are expected to provide the design guidelines for the applications of shape memory alloys.
Keywords
Thermal-induced phase transformation, transformation temperature, molecular dynamics, crystal variants
Cite This Article
Chen, H., Tsou, N. (2019). The Analysis of Thermal-Induced Phase Transformation and Microstructural Evolution in Ni-Ti Based Shape Memory Alloys By Molecular Dynamics. CMES-Computer Modeling in Engineering & Sciences, 120(2), 319–332.