On the role of imperfections in the failure of a thermal barrier coating made by electron beam deposition

Journal Article · Thu May 11 04:00:00 EDT 2000 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00473-5· OSTI ID:20075936

Mumm, D R; Evans, A G

An impression test has been used to explore the remnant toughness and the delamination characteristics of thermal barrier coatings (TBCs) after extended thermal exposure. The delamination trajectory is found to change as the thermally grown oxide (TGO) thickens. At small thicknesses, delamination occurs predominantly within the TGO and TBC. With a thicker TGO, developed after 100 h exposure at 1,100 C, the delamination extends predominantly along the TGO/bond coat interface, but with small oxide domains remaining embedded in the bond coat. The changes in the interface adhesion and the mechanics responsible for this transition are addressed, along with a discussion of the role of morphological imperfections in the TGO in failure nucleation. A method for determining the effective in-plane modulus of the TBC from the curvature of decohered TGO/TBC bilayers is also presented.

• Research Organization: Princeton Univ., NJ (US)
• OSTI ID: 20075936
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 8 Vol. 48; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COATINGS
DEFECTS
FRACTURE PROPERTIES
INTERFACES
METALS
MORPHOLOGY
OXIDATION
TEMPERATURE RANGE 1000-4000 K
THERMAL SHIELDS