کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5459874 1516192 2017 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dehydrogenation-hydrogenation characteristics of nanocrystalline Mg2Ni powders compacted by high-pressure torsion
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
Dehydrogenation-hydrogenation characteristics of nanocrystalline Mg2Ni powders compacted by high-pressure torsion
چکیده انگلیسی


- Mg2Ni powders were subjected to high pressure torsion.
- HP-DSC was performed on the as-prepared HPT disk.
- Partial hydrogenation and dehydrogenation states were obtained.
- Rietveld analysis was applied to monitor microstructure during hydrogen cycling.
- DSc and TG were performed on the partially desorbed states.

High-pressure torsion technique was applied on nanocrystalline Mg2Ni powders to produce bulk disks by simultaneous uniaxial compression and severe shear deformation. The hydrogen absorption and desorption behavior of the disks has been characterized by high-pressure calorimetry. During desorption, the decomposition of the Mg2NiH4 phase takes place, which is followed by the dehydrogenation of Mg2NiH0.3 solid solution. In order to monitor the sorption properties in details, partially dehydrogenated states of the fully absorbed disk have been performed by interrupting the desorption process at 75%, 50% and 25% hydrogen contents in a Sieverts' type apparatus. Microstructural evolution during dehydrogenation has been investigated by X-ray diffraction. The variation of average crystallite size, lattice parameters and unit cell of the competing phases has been determined by the Rietveld refinement method of X-ray diffractograms. The unit cell volume of the Mg2NiH0.3 hydride solid solution decreases with decreasing hydrogen content. Coupled differential scanning calorimetry and thermogravimetry measurements were also taken on the partially desorbed states in order to determine the activation energy of hydrogen release.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 702, 25 April 2017, Pages 84-91
نویسندگان
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