Kinetics of thermal decomposition of titanium hydride powder using in situ high-temperature X-ray diffraction (HTXRD)

• Main Authors: Hugo Ricardo Zschommler Sandim, Bruno Vieira Morante, Paulo Atsushi Suzuki
• Format: Article
• Language: English
• Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 2005-09-01
• Series: Materials Research
• Subjects: titanium hydride; thermal decomposition; desorption kinetics; X-ray diffraction
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392005000300012
• ISSN: 1516-1439

The thermal decomposition of titanium hydride powder (delta-phase) to titanium (alpha-phase) was investigated by means of thermogravimetric analysis (TGA) and high-temperature X-ray diffraction (HTXRD) in high vacuum. The delta-to-alpha phase transformation was followed in situ by HTXRD at temperatures varying from room temperature up to 1000 °C. The transformation was also analyzed as a function of time at isothermal conditions from 450 to 650 °C. The results of TGA show that the decomposition of the titanium hydride becomes significant at about 450 °C. Above 500 °C the decomposition is completed in times shorter than 50 minutes. The apparent activation energy for hydrogen desorption was found to be 63 ± 6 kJ.mol-1.