Crystal structure and hydrogen storage properties of body centered cubic 52Ti–12V–36Cr alloy doped with Zr7Ni10

Abstract The crystal structure and hydrogen sorption properties of 52Ti–12V–36Cr doped with Zr 7 Ni 10 have been investigated. Two doping methods were used: (i) melting all the components together (single melt) and (ii) melting the alloy and Zr 7 Ni 10 separately and thereafter re-melting them together (co-melt). The XRD patterns of both single melt and co-melt samples showed that these alloys crystallize in a body centered cubic (BCC) crystal structure. Upon hydrogenation, both doped 52Ti–12V–36Cr BCC alloys turns into Face Centered Cubic (FCC) phase. The single melt alloy exhibits a zirconium and nickel rich phase at the grain boundaries. This phase is well-distributed into the matrix and makes a connected network. The same network microstructure was observed in the co-melt. The single melt alloy exhibits an incubation time before its first hydrogenation (activation) whereas the co-melt alloy immediately started to absorb hydrogen. For both samples, the subsequent hydrogenation kinetic is fast. The maximum hydrogen capacities of the single melt and co-melt alloy are respectively 3.4 and 3.2 wt.%, but the high stability of these hydrides prevents them to desorb at room temperature. Single melt and co-melt alloys have similar thermodynamic parameters.