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

Abstract 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 Cr 1.97 Ti 1.07 phase, Cr 2 Ti 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) 65 V 35 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) 65 V 35 alloy are 2.86% (mass fraction) and 61%, respectively.