Mg_(95)Ni_5-30wt%La_(0.7)Mg_(0.3)Ni_(2.8)Co_(0.5)复合物的吸放氢性能研究  

Investigation on the hydriding/dehydriding properties of Mg_(95)Ni_5-30wt%La_(0.7)Mg_(0.3)Ni_(2.8)Co_(0.5) composite

作　　者：刘燕芳[1] 朱云峰[1] 华峰[1] 刘志兵[1] 李李泉[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《功能材料》2009年第5期809-812,共4页Journal of Functional Materials

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA05Z110)

摘　　要：先采用氢化燃烧合成法制备Mg95Ni5,然后将氢化燃烧合成产物与30%(质量分数)La0.7Mg0.3Ni2.8Co0.5合金进行机械球磨复合,球磨时间分别为5、10、15和20h;将Mg95Ni5的氢化燃烧合成产物直接球磨10h用于对比研究。采用X射线衍射仪、扫描电镜、能谱仪及气体反应控制器研究了材料的相组成、微观形貌、颗粒化学成分以及吸放氢性能。研究表明,球磨10h的Mg95Ni5/La0.7Mg0.3Ni2.8Co0.5复合物具有最佳的吸放氢性能,在373K,50s内基本达到饱和吸氢量3.78%(质量分数);在523K,1800s内放氢量为3.83%(质量分数);其起始放氢温度为425K,与Mg95Ni5相比降低了35K,吸放氢性能的改善与复合物的组织结构密切相关。此外,La0.7Mg0.36Ni2.8Co0.5的加入改善了复合物的放氢动力学性能。Mg95Ni5 was prepared by hydriding combustion synthesis （HCS） from the powder mixtures of Mg and Ni,and then the HCS product together with 30wt% La0.7 Mg0.3 Ni2.8Co0.5 alloy were subjected to mechanical milling for 5,10,15 and 20h,respectively. The HCS product was also milled for 10h for comparison. By means of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectrometer （EDX） and gas reaction controller, the phase structure, microstructure and hydriding/dehydriding properties of the composites were studied in detail. It was found the composite milled for 10h had the best hydriding/dehydriding properties. It required only 50s to absorb its saturated hydrogen capacity of 3, 78wt% at 373K and desorbed 3.83 wt% hydrogen within 1800s at 523K. Moreover,the dehydriding temperature onset of the composite was 425K, which was 35K lower than that of Mg95 Nis. The improved hydriding/dehydriding properties were related greatly with the structures of the composites, and the addition of La0.7 Mg0.3Ni2.8 Co0. 5 could improve the dehydriding kinetics of the composites.

关 键 词：镁基储氢合金 氢化燃烧合成 机械球磨 吸放氢性能 复合物 

分 类 号：TG139[一般工业技术—材料科学与工程]