Reversibility of the \(\beta \rightleftharpoons \alpha \) phase transformations in a Pd–Cu solid solution
- 31 Downloads
Thin samples (about 4 μm in thickness) of membrane foil of a Pd–Cu solid solution have been grown on the surface of a SiO2/Si heterostructure by magnetron sputtering. The key features of \(\beta \rightleftharpoons \alpha \) phase transformations have been identified using X-ray diffraction, Auger electron spectroscopy, energy dispersive X-ray microanalysis, and resistivity measurements during a heating–cooling cycle. The results demonstrate that the phase transformations are reversible only in solid solutions containing an excess of copper in the concentration range corresponding to limiting temperatures near the temperature stability limit of the β-phase. Thermal conditions of membrane element operation have been found that ensure stability of the ordered atomic structure of the foil and, accordingly, its high performance. The \(\beta \rightleftharpoons \alpha \) phase transformation has been shown to be reversible after holding the foil at t = 830°C, in a state with a disordered atomic structure, which ensures restoration of its high hydrogen permeability after diffusion bonding to the case of a membrane element.
Keywordspalladium alloys condensed foil phase transformations X-ray diffraction electrical resistance
Unable to display preview. Download preview PDF.
- 1.Burkhanov, G.S., Gorina, N.B., Kol’chugina, N.B., and Roshan, N.R., Palladium alloys for hydrogen energy generation, Ross. Khim. Zh., 2006, vol. 50, pp. 36–40.Google Scholar
- 2.Solovetskii, D.I., Chistov, E.M., and Roshan, N.R., Production of pure hydrogen, Al’ternat. Energ. Ekol., 2004, pp. 43–46.Google Scholar
- 4.Diagrammy sostoyaniya dvoinykh metallicheskikh sistem: Spravochnik (Phase Diagrams of Binary Metallic Systems: A Handbook), Lyakishev, N.P., Ed., Moscow: Mashinostroenie, 1997, vol. 2.Google Scholar
- 5.Hydrogen in Metals, Alefeld, G. and Volkl, J., Eds., Heidelberg: Springer, 1978, vol. 1.Google Scholar
- 6.Evteev, A.V., Ievlev, V.M., Kosilov, A.T., and Prizhimov, A.S, Molecular-dynamics simulation of hydrogen diffusion in Pd, Phys. Met. Metallogr., 2005, vol. 100, no. 2, pp. 179–181.Google Scholar
- 7.Ievlev, V.M., Solntsev, K.A., Maksimenko, A.A., Kannykin, S.V., Belonogov, E.K., Dontsov, A.I., and Roshan, N.R., Formation of thin foil of the ordered Pd–Cu solid solution with a CsCl-type lattice during magnetron sputtering, Dokl. Phys. Chem., 2014, vol. 457, no. 2, pp. 127–130.CrossRefGoogle Scholar
- 8.RF Patent 2 579 413.Google Scholar
- 10.Physical Metallurgy, Cahn, R.W., Ed., Amsterdam: North-Holland, 1965.Google Scholar
- 11.Volkov, A.Yu. and Kruglikov, N.A., Effect of plastic deformation on the kinetics of phase transformations in the Cu–47Pd alloy, Phys Met. Metallogr., 2008, vol. 105, no. 2, pp. 202–211.Google Scholar
- 12.Volkov, A.Yu., Study of the ordering and disordering kinetics in the Cu–40 at. % Pd alloy, Phys. Met. Metallogr., 2001, vol. 92, no. 3, pp. 265–269.Google Scholar
- 13.Volkov, A.Yu., Baraz, V.R., Novikova, O.S., and Polovnikova, E.I., Ordering kinetics in the Cu–47 at % Pd alloy, Izv. Vyssh. Uchebn. Zaved., Fiz., 2012, vol. 55, no. 11, pp. 17–23.Google Scholar