260
A. Vyas et al. / Journal of Alloys and Compounds 475 (2009) 252–260
silicon–carbon (Si–C) compositional powder mixture of
50Ti–15Al–20Si–15C, TiC and Ti5Si3 compounds were pro-
duced.
(iv) The phase change hierarchy for the titanium silicide follows a
transition chain TiSi2 → Ti5Si4 → Ti5Si3, with extra Ti as kinetic
bias when the metastable precursors equilibrate to stable
phases in Ti–Al–Si system.
Acknowledgement
This work was fully supported by a grant from the Research
Grants Council of the Hong Kong Special Administrative Region,
China (RGC Ref. No. 114407).
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The behaviours of two sets of Ti–Al–Si and Ti–Al–Si–C pow-
der mixtures during mechanical alloying have been investigated
in terms of phase formation, microstructure and thermal stability,
and the following conclusions can be drawn:
(i) The metastable precursors of two systems, namely, Ti–Al–Si
and Ti–Al–Si–C can be synthesized by mechanical alloying
to produce amorphous phases and nanocrystalline supersat-
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(ii) In Ti–Al–Si system, faster amorphization occurs when both the
Al and Si contents are 21 at%.
(iii) In Ti–Al–Si–C system, for lower silicon-carbon (Si-C) combina-
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