Investigating Thermal Effects on Morphological Evolution during Crystallisation of hcp Metals: Three-dimensional Phase Field Study

Abstract

Computational models simulating the crystallisation of hexagonal close packed (hcp) metals have traditionally used simple solid/fluid interface anisotropy relations. However, this method does not provide a proper representation of the crystallisation anisotropy, particularly for non-isothermal crystallisation. In this work, we used a phase field (PF) model to investigate the effects of thermal properties (thermal diffusivity and latent heat) on the morphological evolution of hcp metals during crystallisation. The governing equation of the PF model was coupled to the temperature evolution equation, and a three-dimensional model was developed in a finite element framework using COMSOL software. We applied the model to study the crystal formation and evolution of magnesium and yttrium. The unique aspect of this work is that we used Qin and Bhadeshia's three-dimensional interface anisotropic model to accurately simulate solid/fluid interface anisotropy. The results showed that the thermal effects significantly influenced the shape evolution of the crystals and can control the formation of potential sites for void nucleation inside the crystal structures.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Anisotropic models; Computational model; Crystal formation; Crystal morphologies; Finite Element; Governing equations; Hcp metals; Hexagonal close packed; Interface anisotropy; Morphological evolution; Nonisothermal; Phase field modelling; Phase fields; Phase-field models; Potential sites; Shape evolution; Temperature evolution; Three dimensional interface; Three-dimensional model; Void nucleation; Anisotropy; Crystal structure; Crystallization; Finite element method; Magnesium; Mathematical models; Thermal effects; Yttrium; Three dimensional; Crystallisation; Hcp crystal morphology; Thermal effects; Three-dimensional phase field modelling

International Standard Serial Number (ISSN)

1066-7857

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2012 Maney Publishing, All rights reserved.

Publication Date

01 Nov 2012

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