【摘要】 为了改善A2B7型La0.8Mg0.2Ni3.5Co0.2合金的电化学性能,采用熔体快淬技术制备了合金。用XRD、SEM分析了合金的微观结构,用电化学方法测试了合金的电化学性能。结果表明,快淬后,合金具有多相结构,包括两个主相(La,Mg)Ni5及(La,Mg)2(Ni,Co)7和残留相LaNi2.28相,快淬使合金的微观应变增加,柱状晶区域面积较大,合金的晶粒明显细化。快淬使合金的放电容量、平台中值电压降低,电化学循环稳定性提高。更多还原

【Abstract】 In order to improve electrochemical performance of A2B7-type La0.8Mg0.2Ni3.5Co0.2alloy,the alloy was fabricated by casting and melt-spinning.The microstructure of the alloy was characterized by XRD and SEM,and the electrochemical performance of the alloy was measured by electrochemical method.The obtained results show that the as-cast and spun alloy has multiphase structure,composing of two main phases(La,Mg) Ni5and(La,Mg)2(Ni,Co)7as well as a residual LaNi2.28phase.With the increasing quenching rate,the microstrain increases,the columnar crystal zone is larger and the crystal is obvious refined.In addition,the discharge capacity and the medium potential of the plateau decrease and the electrochemical stability of the alloy is enhanced after rapid quenching.更多还原