Improvement of sputtered oxide coating adherence and integrity for turbine airfoil applications

Conference · Mon Jan 01 04:00:00 EST 1979

OSTI ID:5925483

Bayne, M. A.; Busch, R.; Fairbanks, J. W.; Patten, J. W.

Two aspects of the durability of modified ZrO/sub 2/ ceramic thermal barrier coatings for gas turbine airfoils are being investigated. First, adherence of coatings of these materials has historically been difficult to achieve due to mismatch in thermal expansion coefficients and other properties between ceramic coatings and metallic substrates. Second, if the ceramic coatings are discontinuous, as for many plasma sprayed coatings, then condensate from the combustion environment may permeate the coating and volume changes in this condensate during subsequent service cycles may produce coating spallation. The adherence problem is approached in this work by seeking to sputter deposit ceramic coatings over either sputter-etched, closely spaced, high aspect ratio substrate surface cones or by sputter depositing ceramic coatings over sputtered CoCrAlY coatings containing a very high density of columnar voids (leaders). The objective in both instances is to provide a compliant fibrous metal attachment between metal substrate and ceramic coating to absorb property mismatches. Progress in providing the fibrous layers and preliminary evaluation of adherence are discussed. The permeability problem is approached both by providing a continuous and impervious ceramic overlayer, and by coating the ceramic layer with a continuous and impervious metal sealing layer that is not required to provide structural strength or insulation. The merits of both of these approaches and preliminary experimental results are discussed.

• Research Organization: Battelle Pacific Northwest Labs., Richland, WA (USA); Department of Energy, Washington, DC (USA). Div. of Fossil Fuel Utilization
• DOE Contract Number: EY-76-C-06-1830
• OSTI ID: 5925483
• Report Number(s): PNL-SA-7809; CONF-790749-2
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104 -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
AIRFOILS
ALLOYS
ALUMINIUM ALLOYS
CHALCOGENIDES
CHROMIUM ALLOYS
COBALT ALLOYS
DEPOSITION
EXPANSION
GAS TURBINES
MACHINERY
OXIDES
OXYGEN COMPOUNDS
SPUTTERING
SUBSTRATES
SURFACE COATING
THERMAL EXPANSION
TRANSITION ELEMENT COMPOUNDS
TURBINES
TURBOMACHINERY
YTTRIUM ALLOYS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES