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采用机械合金化制备Mg76-xTi12+xNi9Cr3(x=4,8,12,16)合金,通过X射线衍射(XRD)、热分析(DSC)、扫描电子显微镜(SEM)和压强-成分-温度(PCT)分析等方法对合金进行分析和表征。结果表明:Mg76-xTi12+xNi9Cr3(x=4,8,12,16)合金相主要由Mg2Ni相和Ti2Ni相组成,随着球磨时间的增加,合金得到明显的细化且非晶化程度提高。Mg76-xTi12+xNi9Cr3(x=4,8,12,16)合金经过20~80 h球磨后,其贮氢量分别从3.93%,3.82%,3.64%和2.81%下降到2.36%,2.16%,1.81%和2.0%;合金经过活化后,在80 s内吸氢趋于饱和,显示合金良好的吸氢速率。随着Ti/Cr比例的增大以及球磨时间的增加,合金的吸氢速率下降,经过40 h球磨后Mg76-xTi12+xNi9Cr3(x=4,8,12,16)合金氢化物的释氢温度分别为277,255,245和233℃,释氢温度随着Ti含量的增加而降低。
The alloy Mg76-xTi12 + xNi9Cr3 (x = 4,8,12,16) was prepared by mechanical alloying and characterized by X-ray diffraction (XRD), thermal analysis (DSC), scanning electron microscopy (SEM) and pressure- PCT) analysis and other methods of alloy analysis and characterization. The results show that the alloy phase of Mg76-xTi12 + xNi9Cr3 (x = 4,8,12,16) consists mainly of Mg2Ni phase and Ti2Ni phase. The microstructure of Mg76-xTi12 + xNi9Cr3 alloy is obviously refined and the degree of amorphization increases with the increase of milling time. After 20 ~ 80 h milling, the hydrogen storage capacity of Mg76-xTi12 + xNi9Cr3 (x = 4,8,12,16) alloy decreased from 3.93%, 3.82%, 3.64% and 2.81% to 2.36%, 2.16% 1.81% and 2.0%, respectively. After the alloy was activated, the hydrogen absorption became saturated within 80 s, indicating a good hydrogen absorption rate of the alloy. With the increase of Ti / Cr ratio and the increase of ball milling time, the hydrogen absorption rate of the alloy decreases. After 40 h ball milling, the hydrogen release temperature of Mg76-xTi12 + xNi9Cr3 (x = 4,8,12,16) 277, 255, 245 and 233 ℃, respectively. The hydrogen release temperature decreased with the increase of Ti content.