Hydride Cycle Synthesis of Ti0.5V2Cr0.5 Alloy and Its Composites with ZrNi/Zr7Ni10 Additives by a Novel Technological Approach

This study presents, for the first time, the mechanisms governing the formation of the ternary Ti_0.5V₂Cr_0.5 base alloy and its composite alloys (incorporating 4 wt % ZrNi and 4 wt % Zr₇Ni₁₀ activating additives), synthesized via hydride cycle (HC) method. Additionally, the interaction of these alloys with hydrogen was systematically investigated. The synthesis was conducted through two distinct technological routes, each resulting in different formation mechanisms of the final composite materials. XRD analysis confirmed that all synthesized alloys form solid solutions with BCC crystal structure, exhibiting nearly identical lattice parameters. The hydrogen interaction of the synthesized alloys was examined under self-propagating high-temperature synthesis (SHS) and short-term activation method (STAM, 15–30 min). In both cases, the hydrides of FCC structure with hydrogen storage capacities ranging from 2.46 to 3.06 wt % were formed. The desorption temperatures of the synthesized hydrides differ due to the different microstructures of the alloys. Hydrides synthesized via STAM using composites obtained through the first synthesis route exhibited a hydrogen capacity of 3.01 wt % and a lower decomposition temperature characterized by a single endothermic peak at 280°C on the differential thermal analysis (DTA) curve. These findings demonstrate the potential of using Ti_0.5V₂Cr_0.5-based alloys for hydrogen storage applications.