Open Access

ARTICLE

Phase-Field Simulation of δ Hydride Precipitation with Interfacial Anisotropy

by Hailong Nie¹, Xincheng Shi¹, Wenkui Yang¹, Kaile Wang¹, Yuhong Zhao^2,1,3,*

1 School of Materials Science and Engineering, Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy Materials, North University of China, Taiyuan, 030051, China
2 Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, China
3 Institute of Materials Intelligent Technology, Liaoning Academy of Materials, Shenyang, 110004, China

* Corresponding Author: Yuhong Zhao. Email:

Computers, Materials & Continua 2023, 77(2), 1425-1443. https://doi.org/10.32604/cmc.2023.044510

Received 01 August 2023; Accepted 31 October 2023; Issue published 29 November 2023

Abstract

Previous studies of hydride in zirconium alloys have mainly assumed an isotropic interface. In practice, the difference in crystal structure at the interface between the matrix phase and the precipitate phase results in an anisotropic interface. With the purpose of probing the real evolution of hydrides, this paper couples an anisotropy function in the interfacial energy and interfacial mobility. The influence of anisotropic interfacial energy and interfacial mobility on the morphology of hydride precipitation was investigated using the phase-field method. The results show that the isotropy hydride precipitates a slate-like morphology, and the anisotropic hydride precipitates at the semi-coherent and non-coherent interfaces exhibited parallelogram-like and needle-like, which is consistent with the actual experimental morphology. Compared with the coherent interface, the semi-coherent or non-coherent interface adjusts the lattice mismatch, resulting in lower gradient energy that is more consistent with the true interfacial state. Simultaneously, an important chain of relationships is proposed, in the range of ( or ), with the increase of the anisotropic mobility in the y-axis, the gradient energy increases (decreases), the tendency of the non-coherent (semi-coherent) relationship at the interface, and the precipitation rate of hydride decreases (increases). Furthermore, the inhomogeneous stress distribution around the hydride leads to a localized enrichment of the hydrogen concentration, producing a hydride tip. The study of interfacial anisotropy is informative for future studies of hydride precipitation orientation and properties.

---

Keywords

---