SiC Oxidation Protective Coating for Graphite Mould


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In order to exploit the anti-oxidation property of graphite mould, a new type of oxidation protective coating is produced by a pack cementation diffusion coating technique. To enable this material to be used at high temperatures, graphite moulds are coated with Si/SiC slips. The anionic dispersant is added to disperse the slip uniformly, of which the optimal amount is evaluated with viscosity. The graphite mold specimens are surface-modified at 100 °C for 10 minutes in a non-polar polymer aqua-solution, considering the uniform wettability of slip. The surface-modified graphite mold specimen shows better wettability than the nonsurface- modified graphite one when coating process is performed through the slip. The interface-reaction of the specimens is performed at 1450 °C in a reduction atmosphere. The microstructure and composition before and after the pack cementation are observed by SEM and EDS, and the phase identify was performed with XRD. The layer of specimens double-coated by the pack cementation and Si/SiC slip coating method is stable, and properties of SiC coating layer formed on the graphite mould surface are dependent on particle size of starting material, Si, and open-pore size of the graphite mould surface. It is found that larger particle size of Si and smaller open-pore size of the graphite mold were the preferable conditions for the interface produces an optimal reaction which anti-oxidation coating.



Edited by:

Hai-Doo Kim, Hua-Tay Lin and Michael J. Hoffmann




J. W. Kim et al., "SiC Oxidation Protective Coating for Graphite Mould", Key Engineering Materials, Vol. 287, pp. 57-62, 2005

Online since:

June 2005




[1] J.E. Sheehan, K.W. Buesking, B.J. Sullivan, Carbon-carbon composites, Annu, Rev. Mater. Sci. 24 (1994) 19-44.


[2] M.E. Westwood, J.D. Webster, R.J. Day, F.H. Hayes, R. Taylor, Oxidation protection for carbon fiber composites, J. Mater. Sci. 31(1996) 1389-1397.

[3] G. V. Samsanov and E. P. Epik, Coating on Graphite, P. 87 in Coating of High Temperature Materials, Part 1, Ed. By H. Hausner, Plenum, NY, (1966).

[4] J. Chown, R. F. Deacon, N. Singer and A.E.S. White, Refractory Coating on Graphite, P. 81 in Special Ceramics. Ed. By P. Popper. Academic Press, London, (1963).

[5] J. R . Fox, D. A. White, S. M. Oleff, R. D. Boyer, and P. A. Budinger, Mater. Res. Soc. Symp. Proc., 73 (1986) 395.

[6] Cheng LF, Xu YD, Zhang LT, Preparation of a oxidation protection coating for C/C composites by low pressure chemical vapor deposition, Carbon 2000; 38: 1493-1498.


[7] Cairo CAA, Graca MLA, Silva CRM, Bressiani JC, Functionally gradient ceramic coating for carbon/carbon antioxidation protection, J Euro Ceram Soc 2001; 21: 325-329.


[8] O. Paccaud and A. Derre, Silicon Carbide Coating by Reactive Pack Cementation-Part I: Silicon Carbide/Silica Interaction, P. 33 in Chem. Vap. Deposition , No. 1, 2000. 6.


[9] Stern KH. Metallurgical and Ceramic Protective Coatings (1st edn). Chapman & Hall: London, 1996; 1-3, 194-197, 74-75, 152-153, 169.

[10] Zhu QS, Qiu XL, Ma CW, oxidation resistant SiC coating for graphite materials, Carbon 1999; 37: 1475- 1484.


[11] Koo UCH, Yu TH, pack cementation coatings on Ti, AL-Nb alloys to modify the high-temperature oxidation properties, Surf Coat Technol 2000; 126: 171-179.


[12] Olivier P, Alain D, Silicon carbide coating by reactive pack cementation-Part ΙΙ: Silicon monoxide/carbon reaction, Chem Vap Deposit 2000; 6(1): 41-50.


[13] Kato Y, KaKamu K, Hironaka Y, Arai N, Kobayashi N, Pierre GRS, J. Chem. Engng of Jpn 1996; 29: 669-674.

[14] T.J. Whalen and A.T. Anderson, Wetting of SiC, Si3N4, and Carbon by Si and Binary Si Alloys, J. Am. Ceram. Soc., 58(9-10), 396-399 (1975).

[15] E. Carlstrom, M. Person, Steric Stabilization of Silicon Carbide Slips, pp.623-32, in High Tech. Ceramics, Edited by P. Vincenzini, Elsevier Science Pub. Co. Amsterdam, 623, (1987).

[16] Marc J. Ledoux and P. H. Cuong, Silicon Carbide a Novel Catalyst Support for Heterogeneous Catalysis, P. 230 in Cattech, Vol. 5. No. 4, (2001).

[17] J. S. Reed, Priciples of Ceramics Processing, John Wiley & Sons, 623, (1987).

[18] M. E. Washburn and W. S. Coblenz, Reaction-Formed Ceramics, Ceram. Bull. 67(2), 356-363, (1988).