Phase-field modeling of the beta to omega phase transformation in Zr–Nb alloys
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
A three-dimensional elastoplastic phase-field model is developed, using the Finite Element Method (FEM), for modeling the athermal beta to omega phase transformation in Zr–Nb alloys by including plastic deformation and strain hardening of the material. The microstructure evolution during athermal transformation as well as under different stress states, e.g. uni-axial tensile and compressive, bi-axial tensile and compressive, shear and tri-axial loadings, is studied. The effects of plasticity, stress states and the stress loading direction on the microstructure evolution as well as on the mechanical properties are studied. The input data corresponding to a Zr – 8 at.% Nb alloy are acquired from experimental studies as well as by using the CALPHAD method. Our simulations show that the four different omega variants grow as ellipsoidal shaped particles. Our results show that due to stress relaxation, the athermal phase transformation occurs slightly more readily in the presence of plasticity compared to that in its absence. The evolution of omega phase is different under different stress states, which leads to the differences in the mechanical properties of the material. The variant selection mechanism, i.e. formation of different variants under different stress loading directions, is also nicely captured by our model.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1193641
- Alternate ID(s):
- OSTI ID: 1249879
- Report Number(s):
- LA-UR-14-26568; PII: S0921509315002683
- Journal Information:
- Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing, Vol. 634, Issue C; ISSN 0921-5093
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Formation of stress- and thermal-induced martensitic nanostructures in a single crystal with phase-dependent elastic properties
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journal | October 2019 |
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