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On cracks and delaminations of thermal barrier coatings due to indentation testing: Experimental investigations

Yan, Jin and Leist, Thorsten and Bartsch, Marion and Karlsson, Anette M. (2008):
On cracks and delaminations of thermal barrier coatings due to indentation testing: Experimental investigations.
In: Acta Materialia, pp. 4080-4090, 56, (15), ISSN 13596454, [Online-Edition: http://dx.doi.org/10.1016/j.actamat.2008.04.039],
[Article]

Abstract

Rockwell indentation testing as a method of establishing the interfacial fracture toughness of thermal barrier coatings is investigated. To this end, indentation tests have been systematically performed on coatings with yttria-stabilized zirconia top coat deposited by electron beam physical vapor deposition. Specimens in “as-coated” condition and after heat treatment in air have been studied. Unexpectedly, indentation of the heat-treated samples resulted in smaller delaminations than the as-coated samples, suggesting an increase in fracture toughness for coatings subjected to elevated temperatures. Careful image analyses of the cross-section of the indented area show that the ceramic top coat undergoes a complex damage evolution during indentation that is altered by thermal treatment. The consequences of this are discussed and we note that care must be taken when evaluating fracture parameters for multilayered structures based on indentation testing.

Item Type: Article
Erschienen: 2008
Creators: Yan, Jin and Leist, Thorsten and Bartsch, Marion and Karlsson, Anette M.
Title: On cracks and delaminations of thermal barrier coatings due to indentation testing: Experimental investigations
Language: English
Abstract:

Rockwell indentation testing as a method of establishing the interfacial fracture toughness of thermal barrier coatings is investigated. To this end, indentation tests have been systematically performed on coatings with yttria-stabilized zirconia top coat deposited by electron beam physical vapor deposition. Specimens in “as-coated” condition and after heat treatment in air have been studied. Unexpectedly, indentation of the heat-treated samples resulted in smaller delaminations than the as-coated samples, suggesting an increase in fracture toughness for coatings subjected to elevated temperatures. Careful image analyses of the cross-section of the indented area show that the ceramic top coat undergoes a complex damage evolution during indentation that is altered by thermal treatment. The consequences of this are discussed and we note that care must be taken when evaluating fracture parameters for multilayered structures based on indentation testing.

Journal or Publication Title: Acta Materialia
Volume: 56
Number: 15
Uncontrolled Keywords: Indentation; Thermal barrier coatings (TBC); Interfacial fracture toughness
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Nonmetallic-Inorganic Materials
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
Date Deposited: 18 May 2011 15:19
Official URL: http://dx.doi.org/10.1016/j.actamat.2008.04.039
Identification Number: doi:10.1016/j.actamat.2008.04.039
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