About this Abstract 
Meeting 
2018 TMS Annual Meeting & Exhibition

Symposium

Computational Design and Simulation of Materials (CDSM 2018): Atomistic Simulations

Presentation Title 
Finite Temperature Properties of NiTi from First Principles Simulations: Structure, Mechanics, and Thermodynamics

Author(s) 
Justin Haskins, John Lawson 
OnSite Speaker (Planned) 
Justin Haskins 
Abstract Scope 
We determine the thermodynamic properties of the martensite and austenite phases of the shape memory alloy NiTi from density functional theory molecular dynamics. A statistical procedure involving numerical temperature derivatives and thermal fluctuations is employed to evaluate temperaturedependent structural parameters, elastic constants, coefficients of volume expansion, specific heats, and free energies. The martensitic phase transition temperature is determined from the values of free energy. Anharmonicity is shown to play a large role in the temperature dependent behavior of all computed properties. Of particular note, neglect of anharmonicity in the free energies through the use of the quasiharmonic approximation is shown to introduce a significant error (on the order of hundreds of K) into the computed martensitic transition temperature. 
Proceedings Inclusion? 
Planned: Supplemental Proceedings volume 