机械合金化LaNi_5-31%Mg的结构及性能表征  

Characterization of Structure and Performer of the Mechanically-alloyed LaNi_5-31%Mg Alloy

作　　者：蒙冕武[1] 刘心宇[2] 成钧[3] 周怀营[3] 

机构地区：[1]广西师范大学资源与环境学系,广西桂林541004 [2]中南大学材料科学与工程学院,湖南长沙410083 [3]桂林电子工业学院材料科学与工程研究中心,广西桂林541004

出　　处：《矿冶工程》2004年第4期68-71,共4页Mining and Metallurgical Engineering

基　　金：国家自然科学基金委员会资助 (50 1 71 0 2 4 );广西壮族自治区自然科学基金资助 (0 1 350 53)

摘　　要：采用X -射线衍射 (XRD)、扫描电子显微镜 (SEM)、差热分析 (DTA)及电池性能测试仪等方法研究了LaNi5 3 1%Mg合金的组织形貌、热稳定性能及电化学活化性能等。结果表明 :经 3 0 0r min球磨 2 5 0h后 ,样品中形成了短程有序或无序的镧、镁、镍等非晶及MgNi2 纳米晶 ( 3 .4nm)组织 ;颗粒形状主要为规则的球形或近球形及少量多角形等 ,粒径范围为 0 .12～ 8.70 μm。经 763K保温3 5d ,得到热稳定性较好的具有纳米尺度的Mg2 NiLa ,Mg2 Ni,MgNi2 三相合金。球磨样品在碱性电解液中首次充放电活化时即达到其最大容量 410mAh g 。The microstructure, thermal stability and activation characteristics of the LaNi 5-31%Mg alloy were investigated by XRD,SEM,DTA and battery test apparatus. The results showed that the amorphous structure of La,Mg and Ni and the nanocrystalline structure of MgNi 2 form in the sample after it was ball milled for 250 h at 300 r/min, and their particles were mostly spherical or approximately spherical and a few polygonal, usually 0.12～8.70 μm in particle size. After 45 day of heat preservation at 763 K, the nanoscale Mg 2NiLa-Mg 2Ni-MgNi 2 alloy with a good thermal stability was obtained. The sample reached its maximum discharge capacity(410 mAh/g) in alkaline electrolyte during its first charge/discharge cycle, indicating that it had better activation characteristics at high electrochemical discharging capacity at ambient temperatures.

关 键 词：氢化物 机械合金化 相组成 热稳定性 活化性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程]