热处理对A_2B_7型La_(0.6)Sm_(0.15)Nd_(0.1)Mg_(0.15)Ni_(3.4)Al_(0.1)贮氢合金微观结构和电化学性能的影响  

Influence of Heat Treatment on Microstructure and Electrochemical Properties of A_2B_7La_(0.6)Sm_(0.15)Nd_(0.1)Mg_(0.15)Ni_(3.4)Al_(0.1) Hydrogen Strange Alloy

作　　者：刘黎黎[1] 闫慧忠[2] 曹慧 吉力强 刘阳 姜传博 

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]包头稀土研究院,内蒙古包头014030 [3]内蒙古稀奥科贮氢合金有限公司,内蒙古包头014030

出　　处：《稀土》2016年第2期117-122,共6页Chinese Rare Earths

摘　　要：采用感应熔炼法制备了La_(0.6)Sm_(0.15)Nd_(0.1)Mg_(0.15)Ni_(3.4)Al_(0.1)合金,研究了在975℃下经不同时间(t=0、12h、24 h和48 h)热处理对合金相结构及电化学性能的影响。X射线衍射(XRD)分析表明,熔炼得到的La_(0.6)Sm_(0.15)Nd_(0.1)Mg_(0.15)Ni_(3.4)Al_(0.1)合金由CaCu_5型、Ce_2Ni_7型和Gd_2Co_7型三种晶体结构构成,t=24 h时,合金中仅存在Ce2Ni7型晶体结构。元素分析表明,合金相结构的转变是由于在热处理过程中,合金构成元素的扩散以及Mg元素的烧损造成的。电化学测试表明,随热处理时间的增加,合金电极活化次数变化不大,而最大放电容量、高倍率放电性能呈现先增加后降低的趋势,其中,t=24 h时合金的最大放电容量为363.81 mAh/g,电流密度为1600 m A/g时合金的高倍率放电性能达到92.65%。The La（0.6）Sm（0.15）Nd（0.1）Mg（0.15）Ni（3.4）Al（0.1）was prepared by inductive melting and treated by heating for different time（ t = 0 h,12 h,24 h,48 h） at 975 ℃. The effects of annealing time on microstructure and electrochemical properties were systemically investigated. XRD results indicate that the as- caste alloy consists of CaCu5 type,Ce2Ni7 type and Gd2Co7 type crystals. When the heating treatment time t = 24 h,the alloy contains single phase with Ce2Ni7 type crystal. This transformation is resulted from diffusion of elements in alloy and burning loss of Mg in the annealing process. Going with increasing of t,there are no obvious differences on activation of alloy electrodes. However,the maximum discharge capacity and high rate discharge（HRD） properties increase firstly and then decrease with the increasing of thermal treatment time. When t = 24 h,the maximum discharge capacity of the alloy electrode reaches 363. 81 m Ah / g. Meanwhile,the HRD ability for the alloy electrode treated by heating for 24 h is 92. 56 %,with the discharge current density reaching 1600 m A / g.

关 键 词：LA-MG-NI系贮氢合金 A2B7型贮氢合金 热处理时间 晶体结构 电化学性能 

分 类 号：TG146.6[一般工业技术—材料科学与工程]