Semi-Empirical Force-Field Model for the Ti1−xAlxN (0 ≤ x ≤ 1) System

• Published in: Materials Vol. 12; no. 2; p. 215
• Main Authors: Almyras, G., Sangiovanni, D., Sarakinos, K.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 10.01.2019; MDPI
• Subjects: Bulk modulus; Computer simulation; Defects; Density functional theory; Elastic properties; Energy; Enthalpy; Equilibrium; force-field model; Free energy; Heat of formation; Interatomic distance; interatomic potential; Interstitials; Lattice parameters; Lattice vacancies; MD simulations, molecular dynamics; MEAM; Methods; Optimization; Oxidation; Parameterization; phase stability; Phase transitions; Phases; Physical properties; Solid solutions; spinodal decomposition; Ti-Al-N; Titanium; titanium-aluminum nitride
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12020215

We present a modified embedded atom method (MEAM) semi-empirical force-field model for the Ti1−xAlxN (0 ≤ x ≤ 1) alloy system. The MEAM parameters, determined via an adaptive simulated-annealing (ASA) minimization scheme, optimize the model’s predictions with respect to 0 K equilibrium volumes, elastic constants, cohesive energies, enthalpies of mixing, and point-defect formation energies, for a set of ≈40 elemental, binary, and ternary Ti-Al-N structures and configurations. Subsequently, the reliability of the model is thoroughly verified against known finite-temperature thermodynamic and kinetic properties of key binary Ti-N and Al-N phases, as well as properties of Ti1−xAlxN (0 < x < 1) alloys. The successful outcome of the validation underscores the transferability of our model, opening the way for large-scale molecular dynamics simulations of, e.g., phase evolution, interfacial processes, and mechanical response in Ti-Al-N-based alloys, superlattices, and nanostructures.