机械合金化制备Mg76-xTi12Ni12Mnx(x=2,4,6,8)合金及其贮氢性能研究

摘要

利用机械合金化法制备了Mg76-xTi12Ni12Mnx(x=2,4,6,8)合金,并研究了Mn添加量对合金贮氢性能的影响.结果表明,在Mg76-xTi12Ni12Mnx(x=2,4,6,8)合金中合金相主要由Mg2Ni和Ti2Ni相组成,合金最大贮氢量分别为3.47%、3.32%、3.60%和3.11%(质量分数,下同),合金氢化物的分解热依次为-79.2kJ/mol、-78.0kJ/mol、-73.7kJ/mol和-73.6kJ/mol,添加Mn可降低合金氢化物的稳定性,改善其热力学性能,非晶化不利于提高合金的贮氢性能.%Mg76-xTi12Ni12Mnx(x=2,4,6,8) alloys were prepared by mechanical alloying and the effects of Mn content on the hydrogen storage properties were investigated systematically. For Mg76-x Ti12Ni12Mnx (x= 2,4,6,8) alloys, the main binary alloy phase is consisted of Mg2 Ni and Ti2 Ni phase, the maximum hydrogen storage capacity is 3. 47wt％,3. 32wt％, 3. 60wt％ and 3.1l wt％ respectively. The hydrides decomposition enthalpies of Mg76-xTi12 Ni12Mnx(x=2,4,6,8) alloys are -79. 2kJ/mol,-78. 0kJ/mol,-73. 7kJ/mol and -73. 6kJ/mol. The stability of Mg76-xTi12Ni12Mnx(x=2,4,6,8) alloy hydride is reduced and the thermodynamics performance is also improved with addition of Mn element. The result shows that amorphous is unfavorable to improve hydrogen storage performance.