Publication detail

Influence of Isothermal Exposure on Microstructural Changes Resulting in Delamination of Eutectic Al2O3+ZrO2+SiO2 Thermal Barrier Coating

JECH, D. ČELKO, L. CHRÁSKA, T. SLÁMEČKA, K. KLAKURKOVÁ, L. DUBSKÝ, J. ŠVEJCAR, J.

Original Title

Influence of Isothermal Exposure on Microstructural Changes Resulting in Delamination of Eutectic Al2O3+ZrO2+SiO2 Thermal Barrier Coating

Type

conference paper

Language

English

Original Abstract

Eutectic ceramic Al2O3-ZrO2-SiO2 also termed Eucor (as a top coat) and CoNiCrAlY (as a bond coat) coatings were sprayed onto the surface of recently developed fine-grained cast polycrystalline nickel-based superalloy Inconel 713 LC by means of water stabilized plasma (WSP) and atmospheric plasma spraying (APS) techniques, respectively. Specimens were subjected to isothermal oxidation at 1050 °C for 10, 50, 100, 200 and 500 hours in ambient atmosphere, prior to which a half of the as-sprayed specimens was annealed at the temperature of 950 °C for 10 hours. Influence of short-time and long-time isothermal exposure on interactions at the bond-coat/top-coat interface was studied. The uniform and continuous oxide layer, also termed the thermally grown oxide (TGO), was formed and grew at the bond-coat/top-coat interface in all samples, both with and without the heat pre-treatment. Relationship between the dwell time, heat treatment and TGO growth kinetics was quantified. Microstructural changes at top-coat/bond-coat interface were investigated by means of a scanning electron microscope equipped with an energy dispersive microanalyzer and by means of image analysis techniques. Delamination of the ceramic top coat in the region near to the top-coat/TGO interface was evocated by stresses initiated in the Eucor top coat due to its shrinkage during cooling.

Keywords

Thermal Barrier Coatings, Thermal Plasma Spraying, Heat Treatment, Electron Microscopy – Scanning, Image Analysis

Authors

JECH, D.; ČELKO, L.; CHRÁSKA, T.; SLÁMEČKA, K.; KLAKURKOVÁ, L.; DUBSKÝ, J.; ŠVEJCAR, J.

RIV year

2014

Released

23. 5. 2014

Publisher

TANGER Ltd.

Location

Ostrava

ISBN

978-80-87294-54-3

Book

Metal 2014

Edition

1

Pages from

885

Pages to

890

Pages count

1981

BibTex

@inproceedings{BUT115657,
  author="JECH, D. and ČELKO, L. and CHRÁSKA, T. and SLÁMEČKA, K. and KLAKURKOVÁ, L. and DUBSKÝ, J. and ŠVEJCAR, J.",
  title="Influence of Isothermal Exposure on Microstructural Changes Resulting in Delamination of Eutectic Al2O3+ZrO2+SiO2 Thermal Barrier Coating",
  booktitle="Metal 2014",
  year="2014",
  series="1",
  pages="885--890",
  publisher="TANGER Ltd.",
  address="Ostrava",
  isbn="978-80-87294-54-3"
}