Study on Microstructure and the Hydrogen Storage Behavior of Ti25VxCr25Nb50-x Multi-Principal Elements Alloys with Customized Parameters

Multi-principal elements alloys show great potential in hydrogen storage due to their severe lattice distortion and wide range of compositional designs, but their highly stable hydrides limit further applications. In this study, the Ti25VxCr25Nb50-x alloys with tailored parameters (VEC = 5) were designed and the microstructure and hydrogen storage behavior of the alloys were investigated. The results show that all alloys consist of a single BCC phase with a dendritic microstructure. Compared to V25 and V35, V15 has the largest lattice constant and the finest dendritic crystals, which are responsible for the excellent hydrogen storage properties of V15. The reversible hydrogen storage capacity of V15 is 1.4 wt.% at 120 °C.