V含量对低钒Ti-V-Cr储氢合金储氢性能的影响

研究了V含量由5at%升高到35at%时,Ti-V-Cr储氢合金组织、相结构及储氢性能的变化.SEM及XRD结果显示:V含量为5at%的Ti-V-Cr合金由Cr1.97Ti1.07相和Cr2Ti相及很少量的Ti相组成;V含量为10at%的Ti-V-Cr合金除了包含前述的3相外还出现了一定量的V基bcc固溶体相;而V含量为35at%的Ti-V-Cr合金转变为以V基bcc固溶体为主相的固溶体储氢合金.随着V含量的升高和组织结构的变化,Ti-V-Cr合金最大吸氢量升高,放氢率也增大,但是吸氢速率显著减小,活化性能变差.室温下,V含量为35at%的合金具有最大的吸氢量并且放氢率也最高,最大储氢量和放氢率分别是2.86%(质量分数)和61%.

The Influences of V Content on Hydrogen Storage Properties in Low Vanadium Ti-V-Cr Alloy

The microstructure and hydrogen storage property changes with V contents from 5aWo to 35at%in Ti-V-Cr alloys were investigated.According to the SEM and XRD results,the microstructure of Ti-V-Cr alloy with 5at%V content consists of Cr1.97Ti1.07 phase,Cr2Ti phase and small amount of Ti phase;besides the phases which is the same as the 5at%one,Ti-V-Cr alloy with 10at%V content still contains an amount of V based solid solution;when V content is up to 35at%,the main phase existing in the Ti-V-Cr alloy is only V based solid solution.Accompanying with the changes of the phase constitution and microstructure,hydrogen storage properties of Ti-V-Cr alloy vary remarkably.With the increase of V content,the maximum hydrogen storage capacity of Ti-V-Cr alloy increases continuously,and the hydrogen desorption ability increases either,but the kinetic and activation properties become worse.Among all the alloys studied,(TiCr)65V35 shows the largest hydrogen storage capacity,and the highest hydrogen desorption ratio at room temperature;Under the condition in the present research,the maximum hydrogen storage capacity and the hydrogen desorption ratio of the(TiCr)65V35 alloy are 2.86%(mass fraction)and 61%,respectively.