Study of the Influence of Refractory Nitride Additives on Hydrogen Storage Properties of Ti6Al4V-Based Materials Produced by Spark Plasma Sintering

This work studied the influence of refractory nitride additives consisting of 5 wt. % each of hexagonal boron nitride (h-BN), titanium nitride (TiN), and aluminium nitride (AIN) on hydrogen storage properties of newly developed Ti6Al4V -based materials by spark plasma sintering. The pure Ti6Al4V alloy displayed a two-phase (α+β) microstructure while the modified composites exhibited apparent microstructural modifications with the appearance of nitride-rich secondary phases. It is discovered that the diffusion process controls the kinetics of hydrogen absorption, leading to a higher rate of absorption at higher temperatures. The additives acted as catalysts, lowered the activation energy and accelerated the rate of hydrogen sorption in the composites relative to the monolithic alloy. Ti6Al4V modified with 5 wt. % h-BN appears to be the most promising candidate for hydrogen storage (2.28 wt. %), which may be competitive for use in applications involving short-range continuous vehicles (~50-100km) and large-scale stationary storage cylinders in hydrogen production locations, and hydrogen filling stations.