from the conferences organized by TANGER Ltd.
Palladium membranes have a high selectivity for hydrogen, which is coupled with their temperature and mechanical stability. Such a selectivity of palladium membranes makes the membrane method the single procedure that allows one to prepare the high-purity hydrogen (no less than 99.9999 vol%) being the main energy carrier in hydrogen power engineering. Palladium-rare earth metal solid solutions are possible hydrogen diffusion membrane alloys, since they exhibit the mechanical stability during the permeation along with the high hydrogen permeability characteristic. Palladium-samarium alloys of nominal compositions Pd-2.6, 3.2, 5.2, 6.8, 8.3, 9.5, and 11 at% Sm were prepared by arc melting; ingots were subjected to free forging and cold rolling to a thickness of 50 µm with intermediate annealing. Vickers hardness, ultimate tensile strength, and relative elongation, were determined and the hydrogen permeability was measured. Within the solid-solution compositions, the strengthening takes place; the ultimate strength increases from 200 MPa (for Pd) to 830 MPa for Pd-8.3 аt% Sm. In this case, the relative elongation remains close to that of pure Pd (21 %). Such mechanical characteristics favor the manufacturing ultrathin foils and show promise for using them in high-performance membranes and membrane elements. The alloys demonstrate the high hydrogen permeability at 300 – 600 K, which is higher substantially as compared to that of Pd alloys alloyed with other elements. Variations of mechanical properties and hydrogen permeability are discussed from the viewpoint of the possible ordering of the solid solutions and formation of hydride phases.
Keywords: Palladium-samarium alloys, solid solution, foil, hydrogen permeability, mechanical properties© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.