Development of an Interatomic Potential for the Simulation of Defects, Plasticity and Phase Transformations in Titanium

Abstract

New interatomic potentials describing defects, plasticity and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics (MD) method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method (LSMC): these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformation and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties, and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single EAM potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. A temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.

References in corpus (12)

• Interatomic potentials for atomistic simulations of the Ti-Al system
• The Effect of Lattice Vibrations on Substitutional Alloy Thermodynamics
• Entropy driven stabilization of energetically unstable crystal structures explained from first principles theory
• Determination of phase diagrams via computer simulation: Methodology and applications to water, electrolytes and proteins
• Classical potential describes martensitic phase transformations between the $\alpha$, $\beta$ and $\omega$ titanium phases
• Free energies of crystalline solids: a lattice-switch Monte Carlo method
• A New Mechanism for the Alpha to Omega Martensitic Transformation in Pure Titanium
• Adjusting the melting point of a model system via Gibbs-Duhem integration: application to a model of Aluminum
• Lattice-switch Monte Carlo
• quasiharmonic equations of state for dynamically-stabilized soft-mode materials
• Density Functional Theory investigations of titanium gamma-surfaces and stacking faults
• Temperature dependence in interatomic potentials and an improved potential for Ti

Cited by in corpus (10)

• Deep Potentials for Materials Science
• Atomistic modelling of all dislocations and twins in HCP and BCC Ti
• Conceptual and practical bases for the high accuracy of machine learning interatomic potential
• Two-step nucleation of the Earth's inner core
• Automated free energy calculation from atomistic simulations
• Ab-Initio Simulation of Field Evaporation
• Understanding the role of anharmonic phonons in diffusion of bcc metal
• Atomistic simulation of martensite microstructural evolution during temperature driven $\beta \to \alpha$ transition in pure titanium
• Competitive B2 and B33 Nucleation during Solidification of Ni50Zr50 Alloy: Molecular Dynamics Simulation and Classical Nucleation Theory
• Phase transitions in titanium with an analytic bond-order potential