**About this Abstract** |

**Meeting** |
**2018 TMS Annual Meeting & Exhibition
** |

**Symposium
** |
**Hume-Rothery Award Symposium: Computational Thermodynamics and Its Implications to Kinetics, Properties, and Materials Design
** |

**Presentation Title** |
Thermodynamic Theory of Mechanical Destrain |

**Author(s)** |
Fei Xue, Yanzou Ji, Long Qing Chen |

**On-Site Speaker (Planned)** |
Long Qing Chen |

**Abstract Scope** |
In the well-known chemical decomposition process, a phase with an initially homogeneous composition separates into two phases with different equilibrium compositions. In this presentation, we demonstrate that phase separation is a much more general process in which the matter involved in the separation can be chemical, mechanical, thermal, etc. In particular, we will discuss a mechanical destrain process in which a phase with a homogeneous strain separates into two phases with different equilibrium strains. Within the destrain model, we will discuss the phase rule, lever rule, equilibrium conditions, and coherent/incoherent strain spinodals. Using the cubic to tetragonal ferroelastic transition as an example, we study the possible destrain and spinodal phenomena and calculate the strain-strain and strain-temperature phase diagrams for a number of ferroelastic transitions. The proposed destrain theory complements the existing chemical decomposition theory and can guide the analysis and design of multi-domain/multi-phase structures during phase transitions involving structural changes. |

**Proceedings Inclusion?** |
Planned: Supplemental Proceedings volume |