摘要
用XRD,SEM对感应熔炼法制备的MlNi_(5-x)(CoMnAl)_x(Ml为富镧混合稀土)贮氢合金的结构和组织进行了研究,结果表明该合金是单相CaCu_5型贮氢合金,其晶格常数为:α=0.50328nm,c=0.39812nm,用混合酸(V_(硝酸):V_(氢氟酸):V_(甘油)=1:2:3)腐蚀能观察到合金的金相组织形貌.铸态合金表层为细晶粒区,心部为粗晶粒区.EPMA分析表明铸态合金中的成分分布不均匀,心部稀土成分明显偏离平均成分.用BS-9300对合金各部位的样品粉末进行电化学性能测试,心部的电化学性能较差。
The microstructure of as-cast MINi_(5-x)(CoMnAl)_x alloy prepared by induction melting under argon (MI denotes La-rich mischmetal)and its influence on the discharge capacity and the cycle stability are investigated by XRD, SEM, EPMA and electrochemical test. The results show that the as-cast alloy is CaCu_5 type signal phase, its lattice parameter is a =0.50328 nm, and c=0.39812 nm. Metallographic structure of the alloy corroded by the mixed acid (V_(nitric acid): V_(hydrofluoric acid): V_(glycerin)= 1: 2: 3) is observed easily. The surface layer of the alloy is fine grain region, its center is coarse grain region. EPMA shows that the alloy composition is not uniform, RE composition of the center region is diverse from the average composition. The electrochemical property of the center region tested by BS-9300 is worse than that of other region.
出处
《广东有色金属学报》
2004年第1期51-54,共4页
Journal of Guangdong Non-Ferrous Metals
