X-ray diffraction and differential scanning calorimetry investigations on high-pressure hydrogen gas charged Ti3Al

Single-phase Ti3Al having DO19 structure (hexagonal) was hydrogenated by ga s charging at a pressure of 3.8 MPa. The stoichiometry of the hydrogenated sample was found to be Ti3AlH4.76. From X-ray diffraction (XRD) measurement s it was found that there were two different hydride phases with fee and hc p crystal structures. By differential scanning calorimetry (DSC) and XRD me asurements the decomposition temperatures of the two hydride phases were id entified. It was found that the hexagonal hydride phase is more stable comp ared to the cubic hydride phase. The decomposition kinetics of the hydride phases were analysed using the DSC data and the decomposition mechanism and the kinetic parameters were obtained. (C) 2000 Elsevier Science B.V. All r ights reserved.