元素取代和磁热处理对La_(0.67)Mg_(0.33)Ni_(3-x)M_x(M=Co,Cu)(x=0,0.5)合金贮氢性能的影响  

Effects of Element Substitution and Magnetic-Heat Treatment on Hydrogen Storage Properties of La_(0.67)Mg_(0.33)Ni_(3-x)M_x(M=Co,Cu)(x=0,0.5) Alloys

作　　者：刘素霞[1] 任雁秋[1] 张捷宇 李谦 周国治[2,3] 赵显久 吴广新 

机构地区：[1]内蒙古科技大学,内蒙古包头014010 [2]上海市现代冶金与材料制备重点实验室,上海200072 [3]北京科技大学,北京100083

出　　处：《稀有金属材料与工程》2011年第4期655-660,共6页Rare Metal Materials and Engineering

基　　金：国家科技部"863"计划(2007AA05Z118);教育部全国优秀博士学位论文作者专项基金(200746);长江学者和创新团队发展计划(IRT0739)

摘　　要：研究了Co和Cu取代Ni以及磁热处理对La0.67Mg0.33Ni3-xMx(M=Co,Cu)(x=0,0.5)合金吸放氢反应热力学和动力学性能的影响。结果表明,Ni被Co和Cu元素部分替代后,合金的吸放氢量增大,放氢温度降低,吸放氢特征时间(tc)减小,吸放氢过程中的扩散活化能降低。磁热处理明显地提高了3种铸态合金的吸氢量,增大了吸放氢平台宽度,改善了合金的吸放氢动力学性能,其中磁热处理对La0.67Mg0.33Ni2.5Co0.5合金改性效果最好,吸放氢量分别为1.40%和1.32%(质量分数,下同),放氢峰所对应的温度为77.8℃,吸放氢特征时间"tc"为91.4和379.3s,吸放氢扩散活化能分别为16.3和23.3kJ/mol。The effects of the substitution of Co and Cu for Ni and magnetic-heat treatment on the thermodynamics and kinetics properties of hydriding/dehydriding reaction for La0.67Mg0.33Ni3-xMx （M=Co,Cu）（x=0,0.5） hydrogen storage alloys were studied. Results show that after the partial substitution of Co and Cu for Ni, the hydrogen absorption/desorption capacity of the alloys is increased, and the temperature of endothermic peak, characteristic time （tc） of hydriding/dehydriding reaction and the activation energy are decreased. The magnetic-heat treatment improves performances of La-Mg-Ni type alloys, including hydrogen absorption capacity, the hydriding/dehydriding platform width and the hydriding/dehydriding kinetics. The thermodynamic and kinetic property of magnetic-heated La0.67Mg0.33Ni2.5Co0.5 alloy is excellent. It can absorb 1.40 wt% H and desorb 1.32wt% H. Its DSC measurement shows endothermic peak of 77.8 oC. The characteristic time （tc） of hydriding/dehydriding reaction is 91.4 and 379.3 s. The hydriding/dehydriding activation energy is calculated to be 16.3 and 23.3 kJ/mol by the Chou model.

关 键 词：La-Mg-Ni型贮氢合金 元素取代 磁热处理 热力学 动力学 

分 类 号：TG139.7[一般工业技术—材料科学与工程]