铸态和快淬态Mm(NiCoMnAl)5合金的电化学性能及相结构

本文研究了铸态和快淬态MmNi3．7Co0．6Mn0．4Al0.3贮氢合金的电化学性能和相结构。电化学测试结果表明：快淬态合金的活化性能比铸态合金差，淬速为10m／s和16m／s的快淬态合金的最大放电容量高于铸态合金，放电电压平台更为平坦。淬速为22m／s和28m／s的快淬态合金的最大放电容量低于铸态合金。随着淬速的增加，合金电极的循环稳定性提高。X射线衍射结果表明：铸态和快淬态合金均由CaCu5型主相和一个第二相组成，快淬使得第二相衍射峰减弱。合金成分更为均匀。快淬态合金的晶格参数大于铸态合金。晶格参数的增加是快淬合金具有良好循环稳定性的一个重要原因。

The Electrochemical Properties and Phase-Structure of the As-cast and Rapid Quenching Mm(NiCoMnAl)5 Alloy

The electrochemical properties and phase structure of the as-cast and quenched MmAl_ 0.3Mn_ 0.4Ni_ 3.7Co_ 0.6 hydrogen storage alloys have been investigated in this paper.The active characters of the quenched alloys were worse than that of the as-cast alloy.The discharge capacities of quenching alloys with quenching rate of 10m/s and 16m/s were higher than that of the as-cast alloy,but it is contrary with the quenching rate of 22m/s and 28m/s.With the increase of the quenching rate,the cycle stability of the quenched alloy increases,and better than that of the as-cast alloy.The as-cast and quenched alloys were composed of CaCu_5-type main phase and a secondary phase.The quenching made the diffraction intensity of the secondary phase decreased.The lattice parameter of the quenched alloys is bigger than that of the as-cast alloy,which is an important reason why the quenched alloys have good cycle stability.