Open Access

ARTICLE

Effect of Modulus Heterogeneity on the Equilibrium Shape and Stress Field of α Precipitate in Ti-6Al-4V

Di Qiu^1,3,4, Rongpei Shi^2,*

1 Materials Genome Institute, Shanghai University, Shanghai, 200444, China
2 School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
3 Shanghai Frontier Science Center of Mechanoinformatics, Shanghai University, Shanghai, 200444, China
4 Zhejiang Laboratory, Hangzhou, 311100, China

* Corresponding Author: Rongpei Shi. Email:

(This article belongs to the Special Issue: Computational Design and Modeling of Advanced Composites and Structures)

Computer Modeling in Engineering & Sciences 2024, 140(1), 1017-1028. https://doi.org/10.32604/cmes.2024.048797

Received 19 December 2023; Accepted 07 February 2024; Issue published 16 April 2024

Abstract

For media with inclusions (e.g., precipitates, voids, reinforcements, and others), the difference in lattice parameter and the elastic modulus between the matrix and inclusions cause stress concentration at the interfaces. These stress fields depend on the inclusions’ size, shape, and distribution and will respond instantly to the evolving microstructure. This study develops a phase-field model concerning modulus heterogeneity. The effect of modulus heterogeneity on the growth process and equilibrium state of the α plate in Ti-6Al-4V during precipitation is evaluated. The α precipitate exhibits strong anisotropy in shape upon cooling due to the interplay of the elastic strain and interfacial energy. The calculated orientation of the habit plane using the homogeneous modulus of α phase shows the smallest deviation from that of the habit plane observed in the experiment, compared to the case where the homogeneous modulus of β phase is adopted. In addition, the equilibrium volume of α phase within the system using homogeneous β modulus exhibits the largest dependency on the applied stresses. The stress fields across the α/β interface are further calculated under the assumption of modulus heterogeneity and compared to those using homogeneous modulus of either α or β phase. This study provides an essential theoretical basis for developing mechanics models concerning systems with heterogeneous structures.

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Keywords

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