( 1. 内蒙古科技大学 材料学院， 包头 014010;
2. 钢铁研究总院 功能材料研究所， 北京 100081)
摘 要: 对AB5型LaxMm1-x(NiMnSiAlFe)4.9(x=0, 0.45, 0.75, 1.00， 摩尔分数)贮氢合金进行了快淬处理， 研究了La含量及快淬工艺对合金微观结构及电化学循环稳定性的影响。 结果表明： La含量的增加对铸态合金的循环稳定性没有明显影响，但使快淬态合金的循环稳定性下降， 且快淬处理能显著提高合金的循环稳定性。 当La替代量从0增加到1.00时， 经300次充放循环后，铸态合金的容量保持率（Rh）从59.2%增加到59.8%； 16 m/s淬速快淬态合金的容量保持率从83.9%下降到65.0%。 对于x=0.45的合金，当淬速从0(铸态被定义为淬速等于0)增加到28 m/s时，容量保持率从59.8%增加到75.8%。
关键字: 无钴AB5型贮氢合金； 快淬工艺； 微观结构；循环稳定性
storage alloy prepared by casting and
rapid quenching
（ 1. School of Materials, Inner Mongolia University of Science and Technology,
Baotou 014010, China;
2. Institute of Functional Material Research,
Central Iron and Steel Research Institute, Beijing 100081, China）
Abstract: In order to improve the electrochemical cycle stability of the Co-free AB5-type hydrogen storage alloy, Co-free LaxMm1-x(NiMnSiAlFe)4.9 (x=0, 0.45, 0.75, 1.00, mole fraction) hydrogen storage alloys were treated by rapid quenching. The effects of the substituting Mm with La and the quenching rate on the microstructure and the electrochemical cycle stability of the as-cast and quenched alloys were investigated. The obtained results show that the influence of substituting Mm with La on the cycle stability of the as-cast alloys is insignificant, but its influence on that of the as-quenched alloys is notable, and rapid quenching can remarkably enhance the cycle stability of the alloys. When the amount of substituting Mm with La increases from 0 to 1.00, the capacity retaining rate (Rh) of as-cast alloys increases from 59.2% to 59.8% after 300 charge-discharge cycles with the current density of 300 mA/g, and for the as-quenched (16 m/s) alloy, it decreases from 83.9% to 65.0%. When the quenching rate increases from 0 (the as-cast is defined as the quenching rate of 0 m/s) to 28 m/s, the capacity retaining rate (Rh) of La0.45 alloy increases from 59.8% to 75.8%.
Key words: Co-free AB5-type hydrogen storage alloy; rapid quenching; microstructure; cycle stability
