Effect of vacuum annealing on the phase stability of Ti3SiC2

Abstract

The effect of vacuum annealing on the thermal stability and phase transition of Ti3SiC2 has been investigated by X-ray diffraction (XRD), neutron diffraction, synchrotron radiation diffraction, and secondary ion mass spectroscopy (SIMS). In the presence of vacuum or a controlled atmosphere of low oxygen partial pressure, Ti3SiC2 undergoes a surface dissociation to form nonstoichiometric TiC and/or Ti5Si3Cx that commences at ~1200°C and becomes very pronounced at ≥ 1500°C. Composition depth profiling at the near surface of vacuum-annealed Ti3SiC2 by XRD and SIMS revealed a distinct gradation in the phase distribution of TiC and Ti5Si3Cx with depth. © 2007, Wiley-Blackwell. The definitive version is available at www3.interscience.wiley.com