Fatigue cracks in a thermal barrier coating system on a superalloy in multiaxial thermomechanical testing

Bartsch M., Baufeld B., Dalkilic S., Chernova L., Heinzelmann M.

INTERNATIONAL JOURNAL OF FATIGUE, vol.30, no.2, pp.211-218, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 30 Issue: 2
  • Publication Date: 2008
  • Doi Number: 10.1016/j.ijfatigue.2007.01.037
  • Journal Name: INTERNATIONAL JOURNAL OF FATIGUE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.211-218
  • Keywords: gas turbines, thermormechanical fatigue/cycling, crack formation, fatigue crack growth, stress analysis, MECHANICAL FATIGUE, BEHAVIOR
  • Anadolu University Affiliated: Yes

Abstract

Thermal barrier coatings (TBC,) are applied on cooled gas turbine components. Between the heated and cooled surfaces a thermal gradient develops, resulting for constraint components in high multiaxial stresses, which may exceed stresses due to mechanical loading. In order to investigate the damage behaviour of TBC systems under close to reality conditions, thermal mechanical fatigue tests with controlled thermal gradients (TGMF-tests) were performed on coated tubular specimens. The specimen substrate was made from directionally solidified nickel base superalloy IN100 DS, and the coating system comprised a NiCoCrAlY bond coat and a ceramic top coat from partially stabilized zirconia. The stress distribution over the specimen wall, which was generated in the course of one TGMF cycle, has been analysed by linear elastic Finite Element calculations.