Penetration and diffusion of hydrogen in palladium--silver alloys. [10, 20, 23, 26 and 40 Ag-Pd; 230-520/sup 0/C; 1-11 atm]

The hydrogen permeability of Pd-Ag alloys containing 10, 20, 23, 26, and 40 wt percent Ag was studied at temperatures between 230 and 520/sup 0/C and hydrogen pressures between 1 and 11 atm. The highest permeability is found in alloys containing 23 to 26 wt percent Ag over the whole range of temperature and pressure. The temperature dependence of the permeability constant follows the exponential law p = p/sub 0/ exp (-E/sub p//RT). The effect of hydrogen pressure on the permeability of the alloys is described by the equation Q = r + k(p/sub 1//sup 0.8/ - 1). Alloys containing 29 and 40 wt percent Ag give a square-root dependence (Q varies as ..sqrt..p/sub 1/). The parameters describing the diffusion of hydrogen in these alloys (D, D/sub 0/, E/sub D/) have been calculated. (auth)