In this paper we report on some hydrogenation characteristics of beta-Al3Mg2. Pressure-composition-temperature (PCT) absorption curves were obtained in the temperature range 573-658 K up to 4 MPa of H-2-pressure. During the H-absorption process, (beta-Al3Mg2 disproportionates into MgH2 and the solid solution of Al(Mg). This reaction is reversible at the temperatures studied. The enthalpy and entropy of the reaction were determined from the Van't Hoff plot as -62(4) kJ/mol H-2 and -122(6)J/K mol H-2, respectively. A detailed analysis of the sample microstructure at several stages of the absorption and desorption processes has been carried out. The microstructure can be explained by hydrogen diffusion and the disproportionation/recombination reactions of the (3 phase.
Interaction of hydrogen with the β-Al3Mg2 complex metallic alloy: Experimental reliability of theoretical predictions / J. F., Fernandez; Leardini, Fabrice; J., Bodega; C., Sanchez; J. M., Joubert; F., Cuevas; E., Leroy; M., Baricco; M., Feuerbacher. - In: JOURNAL OF ALLOYS AND COMPOUNDS. - ISSN 0925-8388. - ELETTRONICO. - 472:1-2(2009), pp. 565-570. [10.1016/j.jallcom.2008.05.029]
Interaction of hydrogen with the β-Al3Mg2 complex metallic alloy: Experimental reliability of theoretical predictions
LEARDINI, FABRICE;
2009
Abstract
In this paper we report on some hydrogenation characteristics of beta-Al3Mg2. Pressure-composition-temperature (PCT) absorption curves were obtained in the temperature range 573-658 K up to 4 MPa of H-2-pressure. During the H-absorption process, (beta-Al3Mg2 disproportionates into MgH2 and the solid solution of Al(Mg). This reaction is reversible at the temperatures studied. The enthalpy and entropy of the reaction were determined from the Van't Hoff plot as -62(4) kJ/mol H-2 and -122(6)J/K mol H-2, respectively. A detailed analysis of the sample microstructure at several stages of the absorption and desorption processes has been carried out. The microstructure can be explained by hydrogen diffusion and the disproportionation/recombination reactions of the (3 phase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
