Investigator: RNDr. Jiří Čermák, DSc.
Number of Project: 106/07/0010
Agency: Czech Science Foundation
Duration: 01. 01. 2007 - 31. 12. 2009

The aim of the project is (i) to obtain the diffusion coefficients of hydrogen in Mg, Mg-xNi and Mg-xNi-yX alloys with the third element X that shows no significant tendency to hydride formation and (ii) to measure the hydrogen desorption spectras of modified (Mg-xNi-yX)-H alloys by DSC. The alloys will be prepared by ball milling and following pressure compacting and by ball-milling followed by induction melting. Average Ni concentration will be x = 10, 23.5 (eutectic), 40, 54.5 (Mg₂Ni) and 60 wt.%. Alloying elements X will be chosen from group II.-IV. (X: Zn, Ga, In, Si, Ge and Sn) and their concentration y will be in units of weight percent. Characteristics of the samples will be checked by electron microanalysis using SEM/EDAX and by DSC. Experimental temperatures will span from the room temperature up to the solidus. Diffusion coefficients will be obtained by tenzimetric method: The samples will be hydrogenised by gaseous hydrogen in a furnace. Diffusion coefficients will be calculated from time dependence of pressure of hydrogen released from the samples.

J. Čermák, L. Král and I. Stloukal: Hydrogen Diffusion in Hydrogenated Mg and Mg-Mg₂Ni Eutectic Alloy. Kovove Mater. 45, 2007, 305.

J. Čermák, L. Král and B. David: Hydrogen Diffusion in Mg₂NiH₄ Intermetallic Compound. Intermetallics 16, 2008, 508.

J. Čermák, L. Král, B. David and I. Stloukal: Kinetics of Phase Transformations in Mg₂Ni-H System. Solid State Phenomena 138, 2008, 71. (invited paper)

J. Čermák and L. Král: Hydrogen Diffusion in Mg–H and Mg–Ni–H Alloys. Acta Mater. 56, 2008, 2677.
! ! ! 15th place in Top 25 Hottest Articles April - June 2008 ! ! !

J. Čermák, L. Král and I. Stloukal: Kinetics of Hydrogen in Mg₂Ni and in Hydrogenated Mg and Mg-Mg₂Ni Eutectic. METAL 2008 - 17^th International Metallurgical & Material Conference, Hradec nad Moravicí, Czech Republic, May 13-15 2008, CD-ROM.

J. Čermák and B. David: Influence of Phase Composition of Mg₂NiH₄ upon the Hydrogen Desorption Kinetics. Scripta Mater. 59, 2008, 432.

J. Čermák and L. Král: Desorption Kinetics of Hydrogen in Mg₂NiH₄ Hydride and in Hydrogenated Eutectic (Mg/Mg₂Ni)H_x. Def. Dif. For. 283-286, 2009, 639. (Presented as oral contribution on DSL 2008, 4^th International Conference on Diffusion in Solids and Liquids, July 9-11, 2008, Barcelona, Spain)

J. Čermák and L. Král: Interrelation Between Hydrogen Desorption Kinetics and Structure of (Mg₂Ni)H_x and Hydrogenated Eutectic (Mg/Mg₂Ni)H_y. Def. Dif. For. 289-292, 2009, 167. (Presented as poster on DIMAT 2008, 7^th International Conference on Diffusion in Materials, October 28-31, 2008, Lanzarote, Canary Islands, Spain)

J. Čermák and L. Král: Hydrogenation of Mg and Two Chosen Mg–Ni Alloys. Int. J. Hydrogen Energ. 33, 2008, 7464.

J. Čermák: Vodík. Scientific American Czech Edition 9, 2009, 19.

L. Král and J. Čermák: Changes of Structure in Mg-Ni Alloys after Absorption and Desorption of Hydrogen. METAL 2008 - 17^th International Metallurgical & Material Conference, Hradec nad Moravicí, Czech Republic, May 13-15 2008, CD-ROM.