Prediction of hydrogen permeability in V-Al and V-Ni alloys

A semi-empirical methodology for predicting the permeability of hydrogen in metallic alloys is proposed by combining an atomistic simulation and a thermodynamic calculation. An atomistic simulation based on a modified embedded-atom method interatomic potential and a CALPHAD-type thermodynamic calculation technique was used to predict the diffusivity and solubility of hydrogen, respectively. The approach was applied to the prediction of the hydrogen permeability in V-Al and V-Ni alloys that are promising for non-Pd hydrogen separation membranes. The predicted permeability of hydrogen decreases, as Al or Ni concentration increases in the alloys. The predicted permeability is in quite good agreement with experimental data available in literature, successfully reproducing the overall trend for the effect of alloying elements, which enables an alloy design of metallic hydrogen permeable membranes.