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 5at% 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; Ti-V-Cr alloy with 10at% V content still contains an amount of V based solid solution besides the phases which are the same as the 5at% one; 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 too, 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.