Microstructural characterization of bulk Ti₃AlC₂ ceramics

Abstract

The microstructural characteristics of the bulk Ti₃AlC₂ ceramic, synthesized by a solid–liquid reaction and simultaneous in-situ hot pressing, have been studied by electron diffraction and high-resolution transmission electron microscopy. It was found that the as-synthesized ceramic is fully dense and free from amorphous phase at the grain boundaries. The ceramic is predominantly a single phase of hexagonal Ti₃AlC₂ with a minor volume of tetragonal Al₃Ti and cubic TiC. The Al₃Ti grains are crystallographically independent of the Ti₃AlC₂, whereas TiC is intergrown with Ti₃AlC₂, forming thin platelets and maintaining a close orientational relationship with the Ti₃AlC₂ matrix.

Acknowledgements

This work was supported by the Natural Sciences Foundation of China (grant No. 50232040) and the National Outstanding Young Scientist Foundation (Y. C. Zhou, No. 59925208; X. L. Ma, No. 50325101). X. L. Ma would like to thank Prof. Dr U. Köster, Department of Chemical Engineering, University of Dortmund, Germany, and the Alexander von Humboldt Foundation, for the invitation to visit the above department in 2002, during which some of the micrographs presented in this paper were recorded on a Philips CM200 transmission electron microscope. X. L. Ma is also grateful to the Hundred Talents Project of the Chinese Academy of Sciences and the Special Funds for the Major State Basic Research Project of China (No. 2002CB613503).