The hydrogen diffusion and phase transformation in a titanium particle were studied based on thermodynamic calculation. The mechanisms of hydrogen diffusion in different phases (α-Ti, β-Ti, TiHx) were analyzed. A mobility database was developed for titanium–hydrogen system based on the experimental works on hydrogen diffusion coefficient reported in literature and the fundamental of diffusion. To implement the calculation, a commercial software package for the simulation of diffusion-controlled phase transformation was used. The hydrogen diffusion process, hydrogen distribution, phase transformation and phase growth rate during hydrogenization of a titanium particle at temperatures of 560, 800 and 1000K were considered. The thermodynamic and kinetic analysis provided quantitative insights into the diffusion process and improved the understanding of diffusion mechanism and phase transformation.

Thermodynamics Approach to the Hydrogen Diffusion and Phase Transformation in Titanium Particles. W.Gao, W.Li, J.Zhou, P.D.Hodgson: Journal of Alloys and Compounds, 2011, 509[5], 2523-9