Chemo-elastic phase-field simulation of the cooperative growth of mutually-accommodating Widmanstatten plates

JOURNAL OF ALLOYS AND COMPOUNDS

卷:767

Article

Amos, P. G. Kubendran¹  Schoof, Ephraim^1,2  Schneider, Daniel^1,2  Nestler, Britta^1,2 

[1] KIT, Inst Appl Mat IAM CMS, Str Forum 7, D-76131 Karlsruhe, Germany

[2] Karlsruhe Univ Appl Sci, Inst Digital Mat Sci IDM, Moltkestr 30, D-76133 Karlsruhe, Germany

关键词: Widmanstatten ferrite;    Self-accommodating plates;    Phase-field model;    Chemo-elastic transformation;    Austenite decomposition;    CALPHAD;    Steel;   

DOI  :  10.1016/j.jallcom.2018.07.138

来源: Elsevier

【 摘 要 】

A comprehensive understanding of the phase transformations is of primary importance to optimize the properties of a material. In the present study, a novel and thermodynamically consistent chemo-elastic multiphase-field model is formulated to simulate phase transformations which yield unique needle-like patterns, referred to as Widmanstatten structure. Owing to the critical role of the curvature in the growth of the Widmanstatten structure, the model is devised to recover the sharp interface solutions, despite the introduction of a diffuse interface. This condition is fulfilled by formulating the chemical and the elastic driving force based on the grand potential density and the mechanical jump conditions, respectively. Additionally, to render a quantitative chemical driving force, parameters from CALPHAD-database (TCFE8) are incorporated. The current work, through the multicomponent multiphase-field simulations, shows that at high temperatures, when the chemical driving force is insufficient to actuate the growth of a plate, the Widmanstatten structure evolves by the co-operative growth of self-accommodating plates. Furthermore, the growth of a single Widmanstatten plate at low temperature is also simulated, and the growth kinetics of the transformations are verified through existing analytical predictions. (C) 2018 The Authors. Published by Elsevier B.V.

【 授权许可】

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