Kinetics of Hydrogen Absorption for Ti33V20Cr47 Alloy Powder

Influences of temperature, initial pressure and particle size on the hydriding reaction kinetics of Ti33V20Cr47 alloy powder was analyzed and discussed. It is found that the rate-controlling step of the hydriding processes is hydrogen diffusion with the activation energy of 25.7 +/- 0.8 kJ/mol. The reaction rate can be accelerated with the increase of temperature. The Ti33V20Cr47 alloy can finish hydrogen absorption faster under the initial pressure 1.5 MPa and 2.5 MPa than under the initial pressure 3.5 MPa because it has two plateaus. The reaction rate can also be accelerated with the increase of particle size. The possible reason could be related to the fact that the large particle size is adverse for the dissipation of reaction heat, thus leading to the rise of the alloy temperature.