Diffusion kinetics of the carburization and silicidation of Ti{sub 3}SiC{sub 2}
- Department of Materials Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States)
The ternary carbide Ti{sub 3}SiC{sub 2} possesses a unique set of properties that could render it a material of considerable technological impact. The motivation for this work was to enhance the hardness and oxidation resistance of Ti{sub 3}SiC{sub 2} by altering its surface chemistry. Reaction of Ti{sub 3}SiC{sub 2} with single crystal Si wafers in the 1200{endash}1350{degree}C temperature range resulted in the formation of a dense surface layer composed of a two phase mixture of TiSi{sub 2} and SiC. This layer grows in two distinct morphologies; an outer layer with fine (1{endash}5 {mu}m) SiC particles and an inner coarser (10{endash}15 {mu}m) one. The overall growth rates of the layers were parabolic. Comparison with previously published results supports the conclusion that diffusion of Si through TiSi{sub 2} is rate limiting. In the 1400{endash}1600{degree}C temperature range, reaction of Ti{sub 3}SiC{sub 2} with graphite foils resulted in the formation of a 15 vol.{percent} porous surface layer of TiC{sub x} (where x{gt}0.8). It is shown that the carburization kinetics are rate limited by the diffusion of C through TiC{sub x}. Both carburization and silicidation increased surface hardness, the latter also enhanced the oxidation resistance by about three orders of magnitude. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 565605
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 83; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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