Thermal properties and thermoelasticity of L1(2) ordered Al3RE (RE = Er, Tm, Yb, Lu) phases: A first-principles study

摘要

Thermal properties and thermoelasticity of L1(2) Al3RE (RE = Er, Tm, Yb, Lu) phases have been studied by first principles calculations combined with density functional perturbation theory and quasi-harmonic approximation. In the temperature range considered, the calculated thermal properties including equilibrium volume, isothermal bulk modulus, Gruneisen parameters for different Al3RE phases exhibit analogous variation tendency and the numerical values are associated with the atomic radius of RE. The calculated thermal expansion and heat capacity for different Al3RE are almost indistinguishable from each other. The obtained elastic constants and polycrystalline elastic moduli exhibit gentle softening trends with temperature, and the variation tendency is also very similar. In the temperature range considered, Al3RE phases are nearly isotropic. The present study would be valuable for future investigation and design of high temperature Al alloys. (C) 2016 Elsevier Ltd. All rights reserved.