Failure of PVD/plasma sprayed thermal barrier coatings during thermal cycling

Conference · Sat Dec 30 23:00:00 EST 1995

OSTI ID:379561

Teixeria, V; Andritschky, M ^[1]; Gruhn, H; Mallener, W; Buchkremer, H; Stoever, D ^[2]

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1. Univ. of Minho, Braga (Portugal)
2. Forschungszentrum Juelich GmbH (Germany)

ZrO{sub 2}7Y{sub 2}O{sub 3} plasma sprayed coatings (PS top coating) were applied on high temperature Ni-based alloys precoated by Physical Vapor Deposition with a thin, dense, stabilized zirconia coating (PVD bond coat). The PS coatings were applied by Atmospheric Plasma Spraying (APS) and Inert gas Plasma Spraying (IPS at 2 bar) for different substrate temperatures. The thermal barrier coatings (TBCs) were tested by furnace isothermal cycling and flame thermal cycling at maximum temperatures between 1,000 C and 1,150 C. The temperature gradients within the duplex PVD/PS thermal barrier coatings during the thermal cycling process were modeled using an unsteady heat transfer program. This modeling enables the authors to calculate the transient thermal strains and stresses which contribute to a better understanding of the failure mechanisms of the TBC during thermal cycling. They have also studied experimentally the adherence and failure modes of these coating systems during this high temperature testing. The TBC failure mechanism during thermal cycling is discussed in the light of coating transient stresses and substrate oxidation.

• OSTI ID: 379561
• Report Number(s): CONF-9509182--; ISBN 0-87170-541-9
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
ADHESION
CHROMIUM OXIDES
CRACK PROPAGATION
CRACKS
DIESEL ENGINES
FRACTURE PROPERTIES
INCONEL 617
INTERFACES
MATERIALS
MATHEMATICAL MODELS
OPTICAL MICROSCOPY
PLASMA ARC SPRAYING
SAMPLE PREPARATION
SCANNING ELECTRON MICROSCOPY
SPUTTERING
TEMPERATURE DEPENDENCE
THERMAL CYCLING
THERMAL STRESSES
TURBINE BLADES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
YTTRIUM OXIDES
ZIRCONIUM OXIDES