快淬工艺对Mg_(2-x)La_xNi(x=0～0.6)合金电化学贮氢性能的影响  

Influence of rapid quenching on electrochemical hydrogen storage performance of Mg_(2-x)La_xNi(x=0-0.6) alloys

作　　者：马志鸿[1,2] 李波[1] 赵栋梁[1] 胡锋[1,3] 张羊换[1,3] 

机构地区：[1]钢铁研究总院功能材料研究所,北京100081 [2]包头稀土研究院,内蒙古包头014010 [3]内蒙古科技大学省部共建国家重点实验室培育基地,内蒙古包头014010

出　　处：《电源技术》2012年第8期1111-1115,1208,共6页Chinese Journal of Power Sources

基　　金：国家自然科学基金项目(50961001;50871050);内蒙古自治区自然科学基金重大项目(2010ZD05)

摘　　要：为了改善Mg2Ni型合金的电化学贮氢性能,用La部分替代Mg,并用铸造及快淬工艺制备了Mg2-xLaxNi(x=0、0.2、0.4、0.6)贮氢合金。用XRD、SEM、HRTEM分析了铸态及快淬态合金的微观结构,用程控电池测试仪测试了合金的电化学贮氢性能,研究了快淬工艺对合金结构及电化学性能的影响。结果发现,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;当La替代量x≥0.4时,合金的主相改变为(La,Mg)Ni3+LaMg3相。La替代Mg提高了Mg2Ni合金的非晶形成能力,快淬态合金均具有明显的纳米晶/非晶结构。快淬对合金电化学性能的影响与合金的成分相关,快淬显著地提高了Mg1.8La0.2Ni合金的电化学贮氢性能,但对于Mg1.4La0.6Ni合金,快淬导致了完全相反的结果,这主要与La替代使合金的主相发生改变相关。In order to improve the electrochemical hydrogen storage performance of the Mg2Ni-type alloys,Mg in the alloy was partially substituted by element La,and melt-spinning technology was used for fabricating the Mg2-xLaxNi（x=0,0.2,0.4 and 0.6） alloys.The structures of the as-cast and spun alloys were characterized by XRD,SEM and HRTEM.The electrochemical hydrogen storage performance of the alloys were tested by an automatic galvanostatic system.The influences of the rapid quenching on the structure and the electrochemical hydrogen storage performances of the alloys were investigated in detail.It is found that the substitution of La for Mg obviously changes the phase composition of the alloys.For x≤0.2,such substitution leads to forming small amount of secondary phases LaMg3 and La2Mg17 without altering major phase Mg2Ni.The major phase of the alloys are changed into the（La,Mg）Ni3＋ LaMg3 phases by increasing La content to x≥0.4.The substitution of La for Mg markedly enhances the glass forming ability of the Mg2Ni-type alloy,and all the as-quenched alloys exhibit a nanocrystalline/amorphous structure.The action of the rapid quenching on the electrochemical performance of the experimental alloys is associated with the chemical composition of the alloys.The rapid quenching notably enhances the electrochemical hydrogen storage performances of the Mg1.8La0.2Ni alloy,but it exerts a completely adverse function for the Mg1.4La0.6Ni alloy,for which the change of the major phase caused by La substitution is responsible.

关 键 词：MG2NI型合金 快淬 La替代Ni 电化学贮氢 

分 类 号：TM912[电气工程—电力电子与电力传动]