ISSN 0004-881X

Effect of Vacuum Annealing on the Thermal Stability of Ti₃SiC₂/TiC/TiSi₂ Composites

by W.K. Pang¹, I.M. Low¹, B.H. O'Connor¹, A.J. Studer², V.K. Peterson² and J.-P. Palmquist³

1) Centre for Materials Research, Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth WA, Australia.
2) The Bragg Institute, ANSTO, PMB 1, Menai, NSW 2234, Australia
3) Kanthal AB, Heating Systems R&D, P.O. Box 502, SE-734 27 Hallstahammar, Sweden.

Abstract

Titanium silicon carbide (Ti₃SiC₂) possesses a unique combination of properties of both metals and ceramics, for it is thermally shock resistant, thermally and electrically conductive, damage tolerant, lightweight, highly oxidation resistant, elastically stiff, and mechanically machinable. In this research, the effect of high vacuum annealing on the phase stability and phase transitions of Ti₃SiC₂/TiC/TiSi₂ composites up to 1550 deg C was studied using in-situ neutron diffraction. The role of TiC and TiSi₂ on the thermal stability of Ti₃SiC₂ during vacuum annealing is discussed. TiC reacts with TiSi₂ between 1400-1450 deg C to form Ti₃SiC₂. Above 1400 deg C, decomposition of Ti₃SiC₂ into TiC commenced and the rate increased with increased temperature and dwell time. Furthermore, the activation energy for the formati Titanium silicon carbide (Ti₃SiC₂) possesses a unique combination of properties of both metals and ceramics, for it is thermally shock resistant, thermally and electrically conductive, damage tolerant, lightweight, highly oxidation resistant, elastically stiff, and mechanically machinable. In this research, the effect of high vacuum annealing on the phase stability and phase transitions of Ti₃SiC₂/TiC/TiSi₂ composites up to 1550 deg C was studied using in-situ neutron diffraction. The role of TiC and TiSi₂ on the thermal stability of Ti₃SiC₂ during vacuum annealing is discussed. TiC reacts with TiSi₂ between 1400-1450 deg C to form Ti₃SiC₂. Above 1400 deg C, decomposition of Ti₃SiC₂ into TiC commenced and the rate increased with increased temperature and dwell time. Furthermore, the activation energy for the formation and decomposition of Ti₃SiC₂ was determined. on and decomposition of Ti₃SiC₂ was determined.

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