中文摘要：

用铸造及快淬工艺制备了La-Mg-Ni系（PuNi3型）电极合金La0．7Mg0．3Ni2．55-xCo0．45Alx（x=0，0．1，0．2，0．3，0．4），研究了快淬工艺对合金微观结构及电化学性能的影响。XRD分析结果表明，铸态及快淬态合金具有多相结构，包括（La，Mg）Ni3相和LaNi5相和一定量的LaNi2相，快淬处理对合金的相组成没有影响，但使相的相对含量产生变化。TEM及SEM分析结果表明，快淬处理显著改善合金的成分均匀性，使晶粒细化。Al替代Ni不利于非晶相的形成，但使快淬态合金的晶粒显著细化。电化学测试结果表明，快淬处理显著提高合金的循环稳定性，但不同程度地降低合金的放电容量和活化性能，快淬对放电电压特性的影响是复杂的。

英文摘要：

La0.7Mg0.3Ni2.55-xCo0.45Alx （x = 0, 0.1, 0.2, 0.3, 0.4） alloys of La-Mg-Ni system （PuNi3-type） for electrodes were prepared by casting and rapid quenching. The effects of the rapid quenching on the mierostruetures and electrochemical performances of specimen alloys were investigated in detail. The results of XRD show that the as-east and rapidly quenched alloys have a multiphase structure of （La, Mg）Ni3 phase, LaNi5 phase and LaNi2 phase. The rapid quenching had an inappreciable influence on the phase compositions of alloys, but obviously changed the relative amount of the phase in the alloys. The results obtained from SEM and TEM demonstrated show that the rapid quenching can significantly improve the composition homogeneity of the alloys and markedly decrease the grain size of the alloys. The substitution of Ni with Al is unfavourable for the formation of amorphous phase in the as-quenched alloys, but leads to the obvious refinement of grains for the as-quenched alloys. The electrochemical measurement indicates that the rapid quenching has a complex influence on the discharge voltage characteristic of the alloys, obviously enhanced the cycle stability, but decreased the discharge capacity and activation capability