Thermally induced acoustic emissions in thermal barrier coatings
- Univ. de Sherbrooke, Quebec (Canada)
- Pratt and Whitney Canada Inc., Longueuil, Quebec (Canada)
In this study, acoustic emission signals are used to monitor the degradation of plasma sprayed Thermal Barrier Coatings (TBC) under thermal cycling conditions. Signal analysis both in time and frequency domains is carried out in order to identify the key parameters which can be used to classify the acoustic emission signals as a function of the damage mechanisms. This classification offers a means of prediction of the long-term behavior of the thermal barrier coating based on the acoustic emission signal signature at the early stages of bench testing. The tests were carried out using an experimental rig that was developed to reproduce thermal conditions encountered inside a combustion chamber. Twelve infrared lamps, each with a power rating of 1,200 W, are used as a heat source. The samples consist of an alloy blade coated with a duplex TBC made of a 150 {micro}m thick bond coat covered with a 300 {micro}m thick partially-stabilized zirconia coating. The maximum surface temperature of the sample was measured to be around 1,000 C. Two broadband transducers are used for acquisition of acoustic emission signals. Measuring the time between signal detection by each of the two transducers provides a means of determination of the location of the source of the acoustic signals. A classification of the signals based on their energy and their maximum peak frequency is presented.
- OSTI ID:
- 379552
- Report Number(s):
- CONF-9509182-; ISBN 0-87170-541-9; TRN: IM9644%%8
- Resource Relation:
- Conference: 1995 National thermal spray conference, Houston, TX (United States), 11-15 Sep 1995; Other Information: PBD: 1995; Related Information: Is Part Of Advances in thermal spray science and technology. Proceedings of the 8. national thermal spray conference; Berndt, C.C.; Sampath, S. [eds.]; PB: 795 p.
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
33 ADVANCED PROPULSION SYSTEMS
COMPOSITE MATERIALS
THERMAL DEGRADATION
ACOUSTIC EMISSION TESTING
NICKEL ALLOYS
COBALT ALLOYS
CHROMIUM ALLOYS
ALUMINIUM ALLOYS
YTTRIUM ALLOYS
ZIRCONIUM OXIDES
YTTRIUM OXIDES
GAS TURBINE ENGINES
PLASMA ARC SPRAYING
THERMAL CYCLING
SIGNALS
CLASSIFICATION
TIME DEPENDENCE
FREQUENCY DEPENDENCE
TEMPERATURE DEPENDENCE
DEFORMATION
THERMAL STRESSES
COOLING
EXPERIMENTAL DATA