Abstract
The oxidation behavior of TiAl coupons coated with a fine-grain Co-30Cr-4Al (mass %) film of about 30-μm thickness has been studied at 1100–1400 K in a flow of purified oxygen at atmospheric pressure for up to 500 ks. Three oxidation stages were recognized: initial transient, parabolic, and accelerated stages. However, at 1100 K a parabolic stage continues for more than 800 ks. The activation energy for parabolic oxidation agrees with reported values for the oxidation of alumina-former alloys, although the mass gains during the parabolic stages are relatively small at 1200 and 1300 K. Micropores developed mainly at the scale/coating and coating/substrate interfaces as oxidation proceeded. This is attributable to recrystallization of the coating during oxidation and a Kirkendall effect due to preferential diffusion of Co into the substrate. The accelerated oxidation can be explained in terms of the formation of rutile mounds on the scale.
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References
Proc. Int. Symp. Intermetallic Compounds, (JIMIS-6), Sendai, O. Izumi, ed. (1991).
H. A. Lipsitt, D. Shechtman, and R. E. Schafrik,Met. Trans. 6A, 1991 (1975).
T. Kawabata, T. Kanai, and O. Izumi,Acta Met. 33, 1355 (1985).
Proc. Workshop on Oxidation of High-Temperature Intermetallics, Cleveland, Toni Grobstein and Joseph Doychak, eds. (1988).
K. Kasahara, K. Hashimoto, H. Doi, and T. Tsujimoto,J. Jpn. Inst. Met. 53, 58 (1989).
Y. Umakoshi, M. Yamaguchi, T. Sakagami, and T. Yamane,J. Mater. Sci. 24, 1599 (1989).
S. Taniguchi, T. Shibata, and S. Itoh,Mater. Trans. JIM 32, 151 (1991).
Preprints on Symp. High-Temp. Oxid. Intermetallic Compounds (in Japanese) (1991).
S. Taniguchi, Rep. the 123rd Committee (in Japanese),JSPS 32, 323 (1991).
Fuhui Wang and Hanyi Lou,Mater. Sci. Eng. A129, 279 (1990).
F. S. Pettit,Trans. TMS AIME 239, 1296 (1967).
J. D. Kuenzly and D. L. Douglass,Oxid. Met. 8, 139 (1974).
S. Taniguchi,J. High Temp. Soc. 15, 125 (in Japanese) (1989).
J. Stringer,Corros. Sci. 10, 513 (1970).
S. Taniguchi,Trans. ISIJ 25, 3 (1985).
S. Taniguchi, T. Shibata, and K. Takeuchi,Mater. Trans. JIM 32, 299 (1991).
G. R. Wallwork and A. Z. Hed,Oxid. Met. 3, 213 (1971).
F. H. Stott, G. C. Wood, and M. G. Hobby,Oxid. Met. 3, 103 (1971).
J. Stringer, I. M. Allam, and D. P. Whittle,Thin Solid Films 45, 377 (1977).
R. Pendse and J. Stringer,Oxid. Met. 23, 1 (1985).
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Taniguchi, S., Shibata, T., Asanuma, N. et al. Oxidation behavior of TiAl coated with a fine-grain Co-30Cr-4Al film. Oxid Met 39, 457–473 (1993). https://doi.org/10.1007/BF00664666
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DOI: https://doi.org/10.1007/BF00664666