IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
artículos
Título:
Hydriding kinetics of Mg\TiH2 fine dispersions obtained by mechanosynthesis
Autor/es:
BIASETTI, ANDRÉS; MENDOZA ZÉLIS, LUIS; MEYER, MARCOS
Revista:
POWDER TECHNOLOGY
Editorial:
ELSEVIER SCIENCE SA
Referencias:
Lugar: Amsterdam; Año: 2016 vol. 307 p. 145 - 152
ISSN:
0032-5910
Resumen:
Mg80\Ti20 hydride systems were prepared viareactive ball milling following two different procedures: grindingMgwithTi or TiH2, in both cases under H2 atmosphere. Such systems were subjected toseveral cycles of hydrogenuptakeand release in volumetric Sieverts apparatus under different pressure andtemperature conditions.Astructural characterization from SEMimages and XRD patterns reveals noessential microstructural differencesbetweenthe samples obtained by different routes, although a growth in domain size withtemperature is observed.Also,the slowing of the kinetics when the temperature goes down is more pronouncedin the specimenfabricatedby the second route.Theinfluence of the transformed and untransformedphase fractions on the absorption kinetics can be well describedusinga double Hill function. Such complex function takes into account two distinguishableprocesses,withandwithout nucleation, that differentiate themselves as temperature increases.The first onemay be relatedtosurface absorption and the second tentatively ascribed to reactions at grainboundaries, dislocations and otherextendeddefects.Thefitted values may then be associated tophysical constants of the processes occurring during hydrogen absorptionin both regions.