Platinum Metals Rev., 1968, 12, (4), 141
Hydrogen Diffusion through Rhodium-Palladium Alloys
Palladium alloys used for the purification of hydrogen by diffusion must not become deformed during the repeated thermal cycles to which they are subjected. Workers at the State Scientific Investigation and Planning Institute for the Rare Metal Industry, Moscow, have now shown (1) the effect of adding rhodium to stabilise alloys used in diffusion equipment by X-ray structural analyses of 1 per cent rhodium-palladium, 1 per cent rhodium-19 per cent silver-palladium and 10 per cent rhodium-palladium. Deformation of the two 1 per cent rhodium alloys after 20 to 800°C thermal cycles was shown to be due to an α⇄β phase change, which altered their volume. 10 per cent rhodium-palladium, which is nearly as permeable to hydrogen as pure palladium, had no phase change, thus explaining its stability in such conditions. However, even 1 per cent rhodium addition significantly increased the stability of 20 per cent silver-palladium.
- 1A. A. Rodina,, M. A. Gurevich and N. I. Doronicheva, Zh. fiz. Khim., 1968, 42, (7), 1822 .