Phase-Field Modeling of Crack Propagation in Polycrystalline Materials

Abstract

A phase-field model based on a modified form of the regularized formulation of Griffith's fracture theory is presented to investigate intergranular and transgranular crack propagations in polycrystalline brittle materials. Grains and grain boundaries are incorporated in the crack initiation and propagation model based on a phase-field model for grain growth, in which the elastic anisotropy varies based on the grain orientation angle, and the grain boundary energy is related to the misorientation angle of the adjacent grains. Correction parameters are utilized in the total free energy functional and mechanical equilibrium equations to consider the effect of material strength on crack nucleation and propagation independent of the regularization parameter. This allows controlling the strength and crack surface energy along the grain boundaries as a function of the misorientation angle in order to mediate intergranular and/or transgranular crack propagation. To demonstrate the capability of the proposed model, intergranular and transgranular crack propagation in ZrB2 bicrystal systems under tensile loading are studied in detail. The effects of grain boundary misorientation angle, grain boundary inclination with respect to initial crack direction, and grain boundary strength (and/or crack surface energy) on the crack propagation path are investigated. Intergranular crack propagation can be promoted by specific combinations of grain boundary strength and crack surface energy, which can contribute to the fracture toughness of polycrystalline materials.

Department(s)

Materials Science and Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Comments

National Science Foundation, Grant FA9550-14-1-0385

Keywords and Phrases

Brittle Fracture; Intergranular Cracking; Phase-Field Model; Polycrystalline; ZrB Ceramics 2

International Standard Serial Number (ISSN)

0927-0256

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 Elsevier, All rights reserved.

Publication Date

15 Jan 2021

Link to Full Text

Share

 
COinS