Ti-Mo合金的吸放氢动力学  

Hydrogen Sorption Kinetics of Ti-Mo Alloys

作　　者：王伟伟[1] 龙兴贵[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《核化学与放射化学》2007年第2期80-84,共5页Journal of Nuclear and Radiochemistry

摘　　要：采用磁悬浮熔炼法制备了5种不同组成的TiMox(x=0.03,0.12,0.25,0.50,1.00,原子比)固溶体合金,用定容变压法测试了其在不同温度范围内的吸放氢动力学性能。研究结果表明,合金的吸放氢动力学可以按一级反应来描述,决速步骤为氢原子在合金晶格中的扩散。相同温度下,不同组成样品的吸氢容量随Mo含量的增加而降低。合金的吸氢活性随Mo含量增加先增强后减弱,氢化物的稳定性随Mo含量的增加而降低。The TiMox solid solution alloys （=r=0.03, 0.12, 0.25, 0.50, 1.00, atomic ratio） are synthesized using the electromagnetic levitation melting technique, and their absorption/ desorption kinetics, hydrogen capacity are quantified. Results reveal that the reactions can be described by the first-order rate law. It is seen that the presence of Mo dramatically lowers the absorption/desorption activation energy, however, the increased concentration of Mo in the samples has an adverse effect on their absorption kinetics and lower their hydrogen storage capacity ,which means the energy level of Ti-Mo-H ternary system rises as the Mo content increases, namely, the increased Mo content lowers the dehydrogenation temperature of the hydride. The hydrogen storage properties also vary with reaction temperature. The hydrogen absorption activation energy, E., is 11.9, 8.0, -6.1, -1.4, 3.3 kJ/mol, respectively. Ea decreases with increasing Mo content and reaches minimum when Mo content is about 0.50, and then increases with more increasing Mo content. The activation energy for hydrogen desorption of TiMox hydrides （x=0. 03, 0.12, 0.25, 0.50, 1.00, atomic ratio）, Ed, is 37. 9, 30. 4, 32. 6, 12. 5 and 13.2 kJ/mol, respectively. Ed decreases as the Mo content increases, but the tendency is not obvious when the Mo content is below 0.50. For the dispersed and activated samples, where the rates are extremely rapid, consideration of possible slow steps for hydrogen sorption must be given to mass transport control.

关 键 词：Ti—Mo合金 氢化物 吸放氢动力学 表观活化能 

分 类 号：TG115.2[金属学及工艺—物理冶金]