Hydrogen-Sorption Properties of the Alloy Ti$_{15.5}$Zr$_{30}$Mn$_{38}$V$_{5.5}$Cr$_{5.5}$Co$_{5.5}$ Based on the Laves Phase (Type $C$14)

Abstract

Microstructure and phase composition of the cast Ti15.5Zr30Mn38V5.5Cr5.5Со5.5 alloy as well as the phase composition of hydrogenation and dehydrogenation products are investigated using the methods of x-ray phase analysis and scanning electron microscopy. As established, due to the partial replacement of manganese with cobalt, it is not possible to expand the area of existence of the Laves phase (type C14), since, in the phase composition of the studied alloy, a second intermetallic phase based on the Zr2Co compound is formed. As determined, the change in the phase composition of the alloy does not affect significantly the kinetics of hydrogen absorption and desorption at the first sorption-desorption cycle. As established, the formed intermetallide based on the Zr2Co compound interacts actively with hydrogen at room temperature and a hydrogen pressure of 0.23 MPa. As shown, the process of hydrogen release begins with the start of heating; at a temperature of 430°C, a reversible capacity of 95% is achieved.