Hydriding and dehydriding characteristics of nanocrystalline and amorphous Mg20-xLaxNi10（x=0-6） alloys prepared by melt-spinning
来源期刊：Journal of Rare Earths2009年第3期
论文作者：张羊换 赵栋梁 任慧平 郭世海 王青春 王新林
文章页码：514 - 519
摘 要：In order to improve the hydrogenation and dehydrogenation performances of the Mg2Ni-type alloys,Mg was partially substituted by La in the alloy,and melt spinning technology was used for the preparation of the Mg20-xLaxNi10（x=0,2,4,6） hydrogen storage alloys. The structures of the alloys were studied by X-ray diffraction（XRD） ,scanning electron microscopy（SEM） and high-resolution transmission electron microscopy（HRTEM） . It was found that no amorphous phase formed in the as-spun La-free alloy,but the as-spun alloys containing La held a major amorphous phase. When La content x≤2,the major phase in the as-cast alloys was Mg2Ni phase,but with further increase of La content,the major phase of the as-cast alloys changed into LaNi5+LaMg3 phase. Thermal stability of the as-spun alloys was studied by differential scanning calorimetry（DSC） ,showing that spinning rate was a negligible factor on the crystallization temperature of the amorphous phase. The hydrogen absorption and desorption kinetics of the as-cast and as-spun alloys were measured using an automatically controlled Sieverts apparatus,confirming that the hydrogen absorption and desorption capacities and kinetics of the as-cast alloys clearly increased with rising La content. For La content x=2,the as-spun alloy displayed optimal hydrogen desorption kinetics at 200 °C.
张羊换1,2，赵栋梁1，任慧平2，郭世海1，王青春2，王新林1
1. Department of Functional Material Research,Central Iron and Steel Research Institute2. School of Material,Inner Mongolia University of Science and Technology
摘 要：In order to improve the hydrogenation and dehydrogenation performances of the Mg2Ni-type alloys,Mg was partially substituted by La in the alloy,and melt spinning technology was used for the preparation of the Mg20-xLaxNi10（x=0,2,4,6） hydrogen storage alloys. The structures of the alloys were studied by X-ray diffraction（XRD） ,scanning electron microscopy（SEM） and high-resolution transmission electron microscopy（HRTEM） . It was found that no amorphous phase formed in the as-spun La-free alloy,but the as-spun alloys containing La held a major amorphous phase. When La content x≤2,the major phase in the as-cast alloys was Mg2Ni phase,but with further increase of La content,the major phase of the as-cast alloys changed into LaNi5+LaMg3 phase. Thermal stability of the as-spun alloys was studied by differential scanning calorimetry（DSC） ,showing that spinning rate was a negligible factor on the crystallization temperature of the amorphous phase. The hydrogen absorption and desorption kinetics of the as-cast and as-spun alloys were measured using an automatically controlled Sieverts apparatus,confirming that the hydrogen absorption and desorption capacities and kinetics of the as-cast alloys clearly increased with rising La content. For La content x=2,the as-spun alloy displayed optimal hydrogen desorption kinetics at 200 °C.
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