Creep of plasma sprayed zirconia. Final Report

Technical Report · Mon Nov 01 04:00:00 EST 1982

OSTI ID:6886435

Firestone, R F; Logan, W R; Adams, J W

Specimens of plasma-sprayed zirconia thermal barrier coatings with three different porosities and different initial particle sizes were deformed in compression at initial loads of 1000, 2000, and 3500 psi and temperatures of 1100 C, 1250 C, and 1400 C. The coatings were stabilized with lime, magnesia, and two different concentrations of yttria. Creep began as soon as the load was applied and continued at a constantly decreasing rate until the load was removed. Temperature and stabilization had a pronounced effect on creep rate. The creep rate for 20% Y2O3-80% ZrO2 was 1/3 to 1/2 that of 8% Y2O3-92% ZrO2. Both magnesia and calcia stabilized ZrO2 crept at a rate 5 to 10 times that of the 20% Y2O3 material. A near proportionality between creep rate and applied stress was observed. The rate controlling process appeared to be thermally activated, with an activation energy of approximately 100 cal/gm mole K. Creep deformation was due to cracking and particle sliding.

• Research Organization: IIT Research Inst., Chicago, IL (USA)
• OSTI ID: 6886435
• Report Number(s): N-83-29393; NASA-CR-167868
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COATINGS
CREEP
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
POROSITY
SPRAYED COATINGS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES