Hydrogen permeation in gamma titanium aluminides

The permeation of hydrogen in gamma titanium aluminides was studied using the Devanathan–Stachurski (DS) cell. Thin disk-shaped samples of gamma titanium aluminide with three different microstructures were appropriately prepared and cathodically charged in an aqueous 0.1 N NaOH solution. The permeation current was monitored as a function of time. Permeation parameters were calculated using the time lag criterion (non-steady state lag). Values of the apparent diffusion coefficient of hydrogen in gamma titanium aluminide varying from 1.87 × 10⁻⁷ cm²/s to 3.75 × 10⁻⁶ cm²/s were obtained. This slight variation is attributed to differences in microstructure.