Mo含量对Ti-Mo氢化物的结构及热稳定性的影响

Effect of Mo on the Structure and Thermal Stability of Ti-Mo Hydrides

采用磁悬浮熔炼技术制备了固溶体合金Ti Mox(x=0.03,0.13,0.25,0.50,1.00,钼钛原子比),室温下活化后的Ti Mox合金在0.02 MPa下迅速吸氢并达到平衡。采用X射线衍射和TG-DSC分析技术对吸氢产物的物相结构和热稳定性进行了测试。作为比较,对吸氢前的合金作了XRD结构分析。结果表明:Ti Mo0.03吸氢后析出大量的Ti H2,并有少量bcc(β-Ti)含氢固溶体存在。x大于0.13时,合金为单一的β-Ti结构,吸氢产物由fcc(γ-Ti)氢化物和β-Ti氢固溶体组成,晶格参数增加至0.330nm,钼含量较少的β-Ti氢固溶体发生相变生成γ-Ti氢化物,Mo含量增加,γ-Ti氢化物含量逐渐减少。β-Ti氢固溶体,γ-Ti氢化物的热解析温度随着Mo含量的增加逐渐降低,说明Mo含量的增加会降低氢化物的稳定性,不利于氢在合金间隙中的储存。

The solid solution alloys TiMox （x = 0. 03, 0. 13, 0. 25, 0. 50, 1. 00, Mo/Ti） were synthesized by electromagnetic levitation technique. In 0.02MPa, the alloys after activation reacted fast with H2 and the alloy hydrides were formed at room temperature. The alloys and their hydrides were investigated hy XRD and thermal properties of the hydrides were studied through TG-DSC analysis. The results show that the alloys form a single hec（β-Ti） phase when x〉0.13. After hydrogenation, besides bcc phase, a new phase Till1.971 （fcc） exists, the phase transformation happens when the lattice parameter is 0. 330nm, and the composition of the new phase decreases as x rises, x= 0.03, the hydride consists in Till2 and Ti-Mo hydrides, and only Ti-Mo hydrides are found when x is over 0.13. The dehydrogenation temperature drops as the Mo content increases, showing that the addition of Mo lowers the thermal stability of Ti-Mo hydrides.