| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Phase Transformations in Ceramics: Science and Applications
|
| Presentation Title |
Prediction of Diffusion-less Phase Transformations |
| Author(s) |
Randall S. Hay, Emmanuel Boakye, Pavel Mogilevsky, Thomas Key |
| On-Site Speaker (Planned) |
Randall S. Hay |
| Abstract Scope |
A general method to predict diffusion-less phase transformations and their associated orientation relationships and habit planes is developed and tested. The method assumes: 1. A superlattice common to the parent and daughter phases is a near-coincidence site lattice (NCSL) that also allows shear in an invariant plane or along an invariant line. 2. NCSLs are calculated for a maximum strain, a maximum shear, a maximum Miller index, and a maximum number of primitive unit cells in the superlattice. 3. Atom shuffles are calculated for motif translations of the daughter phase in fractional increments of NCSL lattice parameters. 4. A transformation is diffusion-less if all atom shuffles are <1/2 bond-length for any motif translation. Predictions are compared with the phenomenological theory for martensitic transformations. Limitations of the method, along with predictions for complex oxides such as rare earth disilicates, are discussed. |