Title

Phase Field Modeling of Stress-Induced Tetragonal-to-Monoclinic Transformation in Zirconia and its Effect on Transformation Toughening

Abstract

This paper proposes a two-dimensional elastic phase field model for capturing the effect of external stress on the tetragonal-to-monoclinic (T → M) phase transformation in zirconia. The model was able to predict the sensitivity of the monoclinic microstructural formation and evolution to the external loading conditions. The effect of stress on the T → M phase transformation was captured by explicitly applying stresses on the computational domain by entering them in the mechanical equilibrium equations as boundary conditions. Simulation results showed that, regardless of the stress loading direction, the monoclinic twinning plane always corresponded to {1 0 0} m. Results of simulations showed that external stress favors the production of monoclinic variants which exhibit transformation strains aligned with the applied stress direction. When applied to the transformation toughening phenomenon in zirconia, the model was able to elucidate the mechanisms of phase transformation ahead of a crack tip, including the generation of a compressive stress field responsible for the retardation of further crack growth. This work presents the first model capable of demonstrating the process of transformation toughening and crack closure in zirconia.

Department(s)

Materials Science and Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Keywords and Phrases

Computational domains; Formation and evolutions; Mechanical equilibrium; Micro-structural; Phase field models; Tetragonal-to-monoclinic transformation; Transformation strain; Transformation toughening; Crack tips; Cracks; Mathematical models; Phase interfaces; Phase transitions; Solid solutions; Stresses; Zirconia

International Standard Serial Number (ISSN)

13596454

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2014 Elsevier Ltd, All rights reserved.

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