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为了改善Mg2Ni型合金气态及电化学贮氢动力学性能,用La部分替代合金中的Ni,用快淬技术制备了Mg2-xLaxNi（x=0、0.2、0.4、0.6）合金,用XRD、SEM、HRTEM分析了铸态及快淬态合金的微观结构;用自动控制的Sieverts装置测试了合金的气态贮氢动力学性能,用程控电池测试仪测试了合金的电化学贮氢动力学。结果发现快淬二元Mg2Ni合金具有典型的纳米晶结构,而快淬La替代合金明显地显示具有非晶结构,表明La替代Mg提高Mg2Ni型合金的非晶形成能力。La替代Mg明显地改变Mg2Ni型合金的相组成。当x≤0.2时,La替代Mg不改变合金的主相Mg2Ni,但出现少量的LaMg3及La2Mg17相。而当La替代量x=0.4时,合金的主相改变为（La,Mg）Ni3＋LaMg3。合金的气态及电化学吸放氢动力学对La含量及快淬工艺敏感,La替代使合金的吸氢动力学降低,但适量的La替代Mg可以明显改善合金的放氢动力学及高倍率放电能力。La替代对合金贮氢动力学性能的影响与合金的制备工艺密切相关,表明合金的组织结构是影响其贮氢动力学的重要因素。

In order to improve the gaseous and electrochemical hydrogen storage kinetics of the Mg2Ni-type alloys,Mg in the alloy was partially substituted by element La,and rapid quenching technology was used for the preparation of the Mg2-xLaxNi（x=0,0.2,0.4,0.6） alloys.The structures of the as-cast and quenched alloys were characterized by XRD,SEM and HRTEM.The gaseous hydrogen storage kinetics of the alloys was measured using an automatically controlled Sieverts apparatus.The electrochemical hydrogen storage kinetics of the alloys was tested by an automatic galvanostatic system.The results show that the as-quenched binary Mg2Ni alloy holds a typical nanocrystalline structure,whereas the as-quenched alloys substituted by La exhibit an evident amorphous structure,implying the substitution of La for Mg facilitates the glass formation of the Mg2Ni-type alloy.The substitution of La for Mg visibly changes the phase composition of the alloys.For x≤0.2,the substitution leads to forming small amount of secondary phases LaMg3 and La2Mg17 without changing major phase Mg2Ni.The major phase of the alloys are changed to the（La,Mg）Ni3＋LaMg3 phases by increasing La content to x≥0.4.The gaseous and electrochemical hydrogen storage kinetics of the alloys is dependent on both the amount of La substitution and the rapid quenching technology.The substitution of La for Mg causes a decrease in the hydrogen absorption kinetics of the alloy,but it significantly ameliorate the hydrogen desorption kinetics and the high rate discharge ability of the alloy.The influence of substituting Mg with La on the hydrogen storage kinetics of the alloy is strongly dependent its preparation technology,meaning that the structure of the alloy is a crucial factor of the hydrogen storage kinetics of the alloy.