EDP Sciences Journals List
Issue J. Phys. IV France
Volume 03, Number C9, Décembre 1993
Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température
Page(s) C9-511 - C9-519
DOI http://dx.doi.org/10.1051/jp4:1993954

Proceedings of the 3rd International Symposium on High Temperature Corrosion and Protection of Materials
Actes du 3ème Colloque International sur la Corrosion et la Protection des Matériaux à Haute Température

J. Phys. IV France 03 (1993) C9-511-C9-519

DOI: 10.1051/jp4:1993954

Oxidation behaviour of simple and Pt-modified aluminide coatings on IN738 at 1100 °C

Y. Niu1, 2, W. T. Wu1, D. H. Boone3, J. S. Smith4, J.Q. Zhang1 and C. L. Zhen1

1  Corrosion Science Lab., Institute of Corrosion and Protection of Metals, Academia Sinica, Shenyang 110015, China
2  Instituto di Chimica, Facoltà di Ingegneria, Universita di Genova, Fiera del Mare, Pad. D, 16129 Genova, Italy
3  Boone and Associates, 2412 Cascade Drive, Walnut Creek, California 94598, U.S.A.
4  Howmet Corporation, Thermatech Coatings Division, 555 Benston Road, Whitehall, Michigan 49461, U.S.A.


Abstract
The oxidation of both low and high-activity simple and Pt-modified aluminide coatings on nickel base superalloy IN738 has been studied in static air at 1100 °C up to 1000 h. For all coatings oxidation followed a parabolic law up to 400 h. The two Pt-modified coatings showed better protectiveness with lower mass gains and smaller rate constants, especially for long reaction times. The presence of Pt significantly improved the resistance to γ'-Ni3Al formation, promoted selective oxidation of aluminium by preventing the transport of other elements outwards to Al2O3 scale and resulted in the formation of purer, slower-growing and more adherent A12O3 scales, delaying the onset of scale spalling for two types of coatings and of oxide nodules growth for the high aluminium activity coating.



© EDP Sciences 1993