Possibility of spinodal decomposition in ZrO{sub 2}-Y{sub 2}O{sub 3} alloys: A theoretical investigation
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
The thermodynamics and kinetics of cubic {yields} tetragonal phase transformations in ZrO{sub 2}-Y{sub 2}O{sub 3} alloys were investigated by using thermodynamic stability analysis and kinetic computer simulations to explore the possibility of a spinodal mechanism during decomposition. Based on a simple free energy model, it is shown that, depending on the alloy composition, a cubic phase aged within the t + c two-phase field may result in three different sequences of phase transformations: (1) direct nucleation and growth of the equilibrium t-phase from the c-phase matrix; (2) formation of a metastable t{prime}-phase followed by nucleation and growth of the equilibrium c- and t-phases; and (3) formation of a transient t{prime}-phase followed by its spinodal decomposition into two tetragonal phases with one of the tetragonal phases eventually transforming to the equilibrium c-phase. The temporal microstructure evolutions for different compositions were studied by using computer simulations based on the time-dependent Ginzburg-Landau (TDGL) model which incorporates the long-range elastic interactions.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 82634
- Journal Information:
- Journal of the American Ceramic Society, Vol. 78, Issue 6; Other Information: PBD: Jun 1995
- Country of Publication:
- United States
- Language:
- English
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