T. E. M. investigations of high toughness non-equilibrium phases in the ZrO sub 2 -Y sub 2 O sub 3 system

Journal Article · Thu Aug 01 00:00:00 EDT 1991 · Scripta Metallurgica; (United States)

OSTI ID:5577201

Lelait, L ^[1]; Alperine, S ^[2]

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1. LEM, CNRS/ONERA, B.P. 72, 92322 Chatillon Cedex (FR)
2. ONERA Materials Science Dept., B.P. 72, 92322 Chatillon Cedex (FR)

Yttria stabilized zirconia ceramic coatings are currently envisaged for thermal insulation of hot stage gas turbine superalloy components. One of the most critical requirements for the application of such ceramic coatings on metallic substrates is a high intrinsic thermomechanical resistance of the ceramic: during service, the thermal expansion coefficient mismatch between metal and ceramic induces high stresses in the composite system. The lack of ductility of the ceramic at service temperatures (1000-1200{degrees}C range) is usually fatal to the coating integrity: coating failure in thermal cycling conditions generally occurs by rapid propagation of a major crack through the ceramic. Thus efficient ceramic coatings for thermal barrier applications must exhibit high intrinsic slow crack growth resistance. This paper reports on TEM studies of high toughness non-equilibrium phases in the ZrO{sub 2}-Y{sub 2}O{sub 3} system.

• OSTI ID: 5577201
• Journal Information: Scripta Metallurgica; (United States), Vol. 25:8; ISSN 0036-9748
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
THERMAL INSULATION
MATERIALS TESTING
THIN FILMS
THERMAL CYCLING
YTTRIUM OXIDES
PHASE STABILITY
STRAIN HARDENING
TRANSMISSION ELECTRON MICROSCOPY
ZIRCONIUM OXIDES
COATINGS
CRACK PROPAGATION
FAILURES
GAS TURBINES
HEAT RESISTING ALLOYS
PHASE STUDIES
RESIDUAL STRESSES
TEMPERATURE RANGE 1000-4000 K
THERMOMECHANICAL TREATMENTS
ALLOYS
CHALCOGENIDES
ELECTRON MICROSCOPY
EQUIPMENT
FABRICATION
FILMS
HARDENING
HEAT RESISTANT MATERIALS
HEAT TREATMENTS
MACHINERY
MATERIALS
MATERIALS WORKING
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
STABILITY
STRESSES
TEMPERATURE RANGE
TESTING
TRANSITION ELEMENT COMPOUNDS
TURBINES
TURBOMACHINERY
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360204 - Ceramics
Cermets
& Refractories- Physical Properties
661300 - Other Aspects of Physical Science- (1992-)
360202 - Ceramics
Cermets
& Refractories- Structure & Phase Studies