Energy-Efficient Hydride Cycle Synthesis of Ti–23Zr–25Nb Alloy

This study focused on synthesizing a Ti–23Zr–25Nb alloy by the energy-efficient hydride cycle (HC) method. The results demonstrated that alloy formation occurs at 1050(16)°C, a temperature is significantly lower than the individual melting points of the alloy components. X-ray powder diffraction analysis revealed that the synthesized alloy consists of two phases: α (hexagonal close packed (HCP) structure, space group P63/mmc) and β (body-centered cubic (BCC) structure, space group Im-3m) solid solutions. The crystal lattice parameters of these phases were determined. Scanning electron microscopy (SEM) revealed distinct microstructural features of the alloy, distinguishing two primary phases with noticeable contrast between light and dark regions. These phases corresponded to those identified by X-ray phase analysis. The interaction of the Ti–23Zr–25Nb alloy with hydrogen in self-propagating high-temperature synthesis (SHS) mode was investigated. It was demonstrated that the compacted alloy, without prior crushing or mechanical treatment, absorbed 2.78(6) wt % hydrogen during the SHS process. Furthermore, X-ray analysis demonstrated that the synthesized hydride of the multicomponent alloy consists of two phases: TiH2 (face-centered cubic (FCC), space group Fm-3m) and TiZrH1.68 (HCP, space group P63/mmc). The thermal stability of the synthesized hydride was analyzed by differential thermal analysis (DTA), revealing hydrogen desorption characterized by two endothermic peaks at 362(2) and 855(4)°C.