快淬对La_(0.67)Mg_(0.33)(NiCo)_3贮氢合金电化学性能的影响  

Influence of the Rapid Quenching on the Electrochemical Properties of La_(0.67)Mg_(0.33)(NiCo)_3 Hydrogen Storage Alloy

作　　者：王国清[1] 张羊换[1] 王煜[1] 董小平[1] 赵栋梁[1] 王新林[1] 

机构地区：[1]钢铁研究总院功能材料研究所,北京100081

出　　处：《稀土》2006年第6期24-27,44,共5页Chinese Rare Earths

基　　金：国家自然科学基金重点项目资助(50131040);内蒙古自然科学基金资助项目(200408020706)

摘　　要：测试了AB3型贮氢合金L a0.67M g0.33(N iCo)3铸态与快淬态的电化学性能,用XRD和SEM测试了合金的微观结构,研究了快淬对AB3型贮氢合金电化学性能的影响。结果表明,快淬使合金的放电容量降低,对合金的活化性能没有明显影响;快淬降低了合金的容量衰减率,提高了合金的循环寿命,其主要原因是快淬使合金的晶粒显著细化。铸态和快淬态合金均具有多相结构,包括斜六面体的(L a,M g)N i3相,六方的L aN i5相及少量的L aN i2相。快淬使合金中的L aN i2相含量增加,这是快淬使合金放电容量下降的一个主要原因。The electrochemical properties of the as-cast and quenched La0.67Mg0.33 （NiCo）3 alloy were measured synthetically, the microstruetures of the alloys were determined by XRD and SEM. The influence of the rapid quenching on electrochemical characteristics and microstructure of the alloy was studied. The obtained results show that rapid quenching decreases the discharge capacity and has no notable effect on the activated performance; rapid quenching reduces the capacity decay rate and extends the cycle life of the alloy, which is attributed to the much smaller grain produced by rapid quenching. All the as-cast and quenched alloys have multi-phase structures, including oblique parallelepiped （La,Mg）Ni3 phase, hexagonal LaNi5 phase and a little of LaNi2 phase. Rapid quenching makes the amount of LaNi2 phase increase, which is regarded as one of the main reasons that rapid quenching decreases the discharge capacity of the alloy.

关 键 词：快淬 AB3型贮氢合金 电化学性能 微观结构 

分 类 号：TG139.7[一般工业技术—材料科学与工程]