Microstructures and hydrogen storage properties of as-cast and copper-mould-cast LaMg_4Ni alloys  

作　　者：范燕平 彭显云 刘宝忠 宿太超 哈日巴拉 

机构地区：[1]School of Materials Science and Engineering, Henan Polytechnic University [2]Cultivating Base for Key Laboratory of Environment-friendly Inorganic Materials in University of Henan Province, Henan Polytechnic University

出　　处：《Journal of Rare Earths》2014年第5期434-438,共5页稀土学报（英文版）

基　　金：Project supported by National Natural Science Foundation of China(51001043,50971112);Program for New Century Excellent Talents in University(NCET-11-0943);China Postdoctoral Science Special Foundation(201104390);Foundation for University Youth Key Teacher of Henan Province(2011GGJS-052);Program for Innovative Research Team(in Science and Technology)in University of Henan Province(2012IRTSTHN007);Doctoral Foundation of Henan Polytechnic University(B2010-13)

摘　　要：Phase compositions, morphologies and hydrogen storage properties of the as-cast and copper-mould-cast LaMgaNi alloys were studied. The dehydriding onset temperature of the as-cast alloy hydride was about 500 K, which was at least 50 K higher than that of the copper-mould-cast one, and the copper-mould-cast alloy hydride had a faster dehydriding rate compared with as-cast one. Additionally, the copper-mould-cast alloy could uptake 2.85 wt.% hydrogen, which was 95.0% of saturated hydrogen storage capac- ity at room temperature. While only 1.80 wt.% hydrogen （60% of saturated capacity） was absorbed for the as-cast alloy under the same conditions. The reversible hydrogen storage capacities and plateau hydrogen pressures of the two alloys were close. X-ray dif- fractions and scanning electron microscopy results indicated that similar thermodynamic property of the two alloys should be ascribed to the same hydrogen storage phase, Mg and MgzNi. The better hydrogen sorption kinetics of copper-mould-cast alloy should be as- cribed to the more uniform phase distribution compared with that of the as-cast one.Phase compositions, morphologies and hydrogen storage properties of the as-cast and copper-mould-cast LaMgaNi alloys were studied. The dehydriding onset temperature of the as-cast alloy hydride was about 500 K, which was at least 50 K higher than that of the copper-mould-cast one, and the copper-mould-cast alloy hydride had a faster dehydriding rate compared with as-cast one. Additionally, the copper-mould-cast alloy could uptake 2.85 wt.% hydrogen, which was 95.0% of saturated hydrogen storage capac- ity at room temperature. While only 1.80 wt.% hydrogen （60% of saturated capacity） was absorbed for the as-cast alloy under the same conditions. The reversible hydrogen storage capacities and plateau hydrogen pressures of the two alloys were close. X-ray dif- fractions and scanning electron microscopy results indicated that similar thermodynamic property of the two alloys should be ascribed to the same hydrogen storage phase, Mg and MgzNi. The better hydrogen sorption kinetics of copper-mould-cast alloy should be as- cribed to the more uniform phase distribution compared with that of the as-cast one.

关 键 词：hydrogen storage copper-mould-cast La-Mg-Ni alloy kinetics THERMODYNAMICS rare earths 

分 类 号：TG139.7[一般工业技术—材料科学与工程]