Thermal barrier coating life prediction model. Annual report

Technical Report · Mon Apr 01 00:00:00 EST 1985

OSTI ID:6810485

Hillery, R V; Pilsner, B H

This is the first report of the first phase of a 3-year program. Its objectives are to determine the predominant modes of degradation of a plasma sprayed thermal barrier coating system, then to develop and verify life prediction models accounting for these degradation modes. The first task (Task I) is to determine the major failure mechanisms. Presently, bond coat oxidation and bond coat creep are being evaluated as potential TBC failure mechanisms. The baseline TBC system consists of an air plasma sprayed ZrO/sub 2/-Y/sub 2/O/sub 3/ top coat, a low pressure plasma sprayed NiCrAlY bond coat, and a Rene'80 substrate. Pre-exposures in air and argon combined with thermal cycle tests in air and argon are being utilized to evaluate bond coat oxidation as a failure mechanism. Unexpectedly, the specimens pre-exposed in argon failed before the specimens pre-exposed in air in subsequent thermal cycles testing in air. Four bond coats with different creep strengths are being utilized to evaluate the effect of bond coat creep on TBC degradation. These bond coats received an aluminide overcoat prior to application of the top coat to reduce the differences in bond coat oxidation behavior. Thermal cycle testing has been initiated. Methods have been selected for measuring tensile strength, Poisson's ratio, dynamic modulus and coefficient of thermal expansion both of the bond coat and top coat layers.

• Research Organization: General Electric Co., Cincinnati, OH (USA)
• OSTI ID: 6810485
• Report Number(s): N-87-13540; NASA-CR-175010; NAS-1.26:175010; R-85AEB304; AR-1; TRN: 87-009883
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PROTECTIVE COATINGS
MECHANICAL PROPERTIES
THERMAL DEGRADATION
SPRAYED COATINGS
EXPERIMENTAL DATA
FAILURES
MATHEMATICAL MODELS
SERVICE LIFE
THERMAL CYCLING
THERMAL INSULATION
YTTRIUM OXIDES
ZIRCONIUM OXIDES
CHALCOGENIDES
COATINGS
DATA
INFORMATION
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties