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采用机械合金化方法制备Mg_3Sb_2金属间化合物,研究了摩尔比为3:2的Mg、Sb混合粉末的机械合金化过程,通过改变球磨转速和球料比找到制备Mg_3Sb_2的最佳工艺参数,对球磨后的粉末进行了X射线衍射(XRD)、差示扫描量热法(DSC)、扫描电镜(SEM)测试分析。结果表明,机械合金化方法可制备出细小的Mg_3Sb_2粉末,最佳球磨工艺参数是500 r/min的球磨转速、15:1的球料比。由热力学计算可知,Mg-Sb二元合成反应的绝热温度Tad=2149.5 K。DSC分析知,随球磨时间的延长,燃烧反应的临界温度会下降。经Kissinger公式计算原始混合粉末的激活能为94.45 k J/mol,球磨2 h之后的激活能为82.23 k J/mol,说明球磨使粉末内部产生大量晶体缺陷和位错等,体系能量增加,反应激活能降低,从而促进合金化的进程。
The mechanical alloying of Mg_3Sb_2 was prepared by mechanical alloying method. The mechanical alloying process of Mg and Sb mixed powders with the molar ratio of 3: 2 was studied. The optimum technological parameters of Mg_3Sb_2 were found by changing the ball milling speed and the ratio of ball material. The powders were characterized by XRD, DSC and SEM. The results show that the fine Mg_3Sb_2 powder can be prepared by the mechanical alloying method. The optimum milling parameters are milling speed of 500 r / min, ball ratio of 15: 1. According to the thermodynamic calculation, the adiabatic temperature Tad of the binary synthesis reaction of Mg-Sb is 2149.5K. DSC analysis shows that with the ball milling time, the critical temperature of the combustion reaction will decline. According to the Kissinger formula, the activation energy of the original mixed powder is 94.45 kJ / mol, and the activation energy after milling for 2 h is 82.23 kJ / mol, which shows that ball milling produces a large amount of crystal defects and dislocations in the powder, Activation can be reduced, thereby promoting the alloying process.