Effect of coating structure on the adherence of sputter-deposited oxide coatings. [ZrO/sub 2/-Y/sub 2/O/sub 3/; Al/sub 2/O/sub 3/-Cr/sub 2/O/sub 3/]
Evaluation of ceramic coatings with graded metal-to-ceramic transition zones and columnar ceramic structures have been completed. The ceramic materials investigated were ZrO/sub 2/.20 Y/sub 2/O/sub 3/, ZrO/sub 2/.8 Y/sub 2/O/sub 3/ and Al/sub 2/O/sub 3/.40 Cr/sub 2/O/sub 3/ deposited over NiCrAlY and CoCrAlY bond layers. Dense ceramic closeout layers were deposited over the columnar ceramic to reduce coating permeability. The majority of the zirconia coatings failed as a result of massive diffusion of aluminum (MCrAlY) and oxygen (ZrO/sub 2/) in the graded metal-ceramic layer. Coating fracture occurred very low in the graded transition zone where a band of Al/sub 2/O/sub 3/ and voids formed. These acted as a preferred path for crack propagation. For this reason, the ZrO/sub 2/ coating which had no graded transition zone performed best in thermal-cycling experiments. Graded Al/sub 2/O/sub 3/ - CoCrAlY layers were less affected by interdiffusion. However, deposition of ceramic layers of Al/sub 2/O/sub 3/.40 Cr/sub 2/O/sub 3/ or ZrO/sub 2/.20 Y/sub 2/O/sub 3/ over graded Al/sub 2/O/sub 3/ - CoCrAlY layers displayed poor adherence.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6016928
- Report Number(s):
- PNL-SA-10842; CONF-830443-3; ON: DE83011804
- Resource Relation:
- Conference: Metallurgical coatings conference, San Diego, CA, USA, 18 Apr 1983
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sputter-deposited metallic and ceramic coatings for heat engines. Work performed from October 1980 to September 1983. [CoCrAlY; ZrO/sub 2/; Al/sub 2/O/sub 3/; Ni-SiC; quartz-SiC]
Development of improved corrosion- and erosion-resistance coatings for gas-turbine airfoils
Related Subjects
ALUMINIUM OXIDES
ADHESION
CHROMIUM OXIDES
COATINGS
YTTRIUM OXIDES
ZIRCONIUM OXIDES
CRACK PROPAGATION
FAILURES
FRACTURES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHROMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
ZIRCONIUM COMPOUNDS
360200* - Ceramics
Cermets
& Refractories