Kinetics and Mechanism of Hydrogen Emission from Titanium Hydride Powder in Air

In this research, DTA and TGA curves of titanium hydride powder in air with the heating rates of 5, 10, 20, 25,30ºC/min were drawn, and XRD patterns of titanium hydride powder during heating rate 10ºC/min were prepared. Results showed that hydrogen comes out of titanium hydride in air during seven stages. And, by increasing heating rate, the mechanism of hydrogen emission from titanium hydride is almost fixed. Upon computation of activation energy of these stages, it was revealed that the mechanism does change at different temperatures. According to DTA curve at 10ºC/min, at temperatures lower than 460ºC, the mechanism is controlled by internal diffusion, at temperatures between 460-650ºC, it is controlled by physicochemical process, and at temperatures higher than 650ºC, it is controlled by chemical reaction. By increasing heating rate, the mechanism is changed at higher temperatures.