Hydrogen Concentration Estimation Based on Density Functional Theory in Aluminum and Alpha Iron under Gaseous Hydrogen Environments

Abstract

Knowledge of the concentration of hydrogen dissolved in materials is essential for the safe design of the components of hydrogen utilization equipment and will help clarify the mechanisms of hydrogen embrittlement. Here, we present a procedure for evaluating the hydrogen concentration in a perfect lattice under practical gaseous hydrogen environments using density functional theory. We employed the condition of chemical potential equilibrium between gaseous hydrogen and dissolved hydrogen in metal as the base equation and evaluated the vibrational energy and entropy at a finite temperature using the small displacement method. The hydrogen concentrations for aluminum and alpha iron obtained by our purely computational approach agree well with experimental data.