利用熔体淬冷法制备出不同速度下的4种合金薄带,研究了快凝对贮氢合金电化学性能的影响。合金的晶体结构采用XRD和SEM进行表征。结果显示,铸态和快凝合金都是单一的CaCu5相结构,快凝后的合金组织变得更加细密,晶粒变小而且更加均匀。电化学实验结果表明,快凝显著提高了合金的稳定性,但是降低了合金的放电容量和高倍率性能,铸态合金和10 m/s速度下的快凝合金综合性能最好。
The structural and electrochemical properties of the as-cast and melt-spun MmNi5-x(CoMn)x alloys were prepared and investigated.Crystal structure of alloys was characterized by XRD and SEM.The results indicated that as-cast and all the spun alloys have the same phase of CaCu5 structure,but the melt-spun alloys showed a homogenous structure of fine columnar grains instead of the loose structure with many defects in the large grains as observed in the as-cast alloy.The electrochemical measurements showed that spinning obviously improved the cycle life of alloys but decreased the discharge capacity and the high rate discharge ability.The cast and the spun alloy of 10 m/s have the best comprehensive electrochemical performance.