Corrosion mechanisms of ZrO2-Y2O3 thermal barrier coatings in the presence of molten middle-east sand

D.J. de Wet; R. Taylor; F.H. Stott

doi:doi:10.1051/jp4:1993969

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) C9-655-C9-663
DOI: 10.1051/jp4:1993969

Corrosion mechanisms of ZrO₂-Y₂O₃ thermal barrier coatings in the presence of molten middle-east sand

D.J. de Wet¹, R. Taylor² and F.H. Stott²

¹ Division of Materials Science and Technology, CSIR, P O Box 395, Pretoria, 0001, South Africa.
² Corrosion [MATH] Protection Centre and Materials Science Centre, UMIST, Manchester, U.K.

Abstract
The deposition of mineral debris in the turbine sections of various jet engines occurred after operation on Middle-East routes. Plasma sprayed ZrO₂-Y₂O₃ thermal barrier coatings were aged with sand samples from several Middle-East locations at temperatures of 1200 to 1500 °C. At temperatures above 1400 °C, the molten sand formed glassy silicate debris that penetrated the ceramic coating completely, resulting in the absorption of ZrO₂ and Y₂O₃ into the silicate. Two corrosion mechanisms were identified, determined by the amount of calcium-based minerals in the sand.