Development of adherent ceramic coatings to reduce contact stress damage of ceramics. Final report

Technical Report · Wed Apr 01 04:00:00 EST 1992

OSTI ID:10175404

D`Angelo, C; Kim, H J; Oblas, D W; Rebenne, H E; Sarin, V K ^[1]

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1. GTE Labs., Inc., Waltham, MA (United States)

High-strength, oxidation-resistant materials for advanced heat engine applications are susceptible to contact stress damage at ceramic/ceramic interfaces. It has been observed that surface damage and strength loss under sliding contact can be substantially reduced by applying a thin ceramic coating. In this program, a multilayered, compositionally graded coating was designed for ceramic components in advanced heat engines. A chemical vapor deposition process was developed for applying coatings in the thickness range of 2--20 {mu}m on 2 in. {times} 1/4 in. {times} 1/8 in. bars. Strongly adherent coatings were grown on the three substrates of interest -- reaction bonded silicon nitride, hot isostatically pressed silicon nitride, and sintered silicon carbide. The effect of the coating on relevant mechanical properties of the substrate materials was evaluated. Performance of the coated material was assessed by conducting long-term high-temperature oxidation and thermal shock tests at 1000{degrees}C and 1200{degrees}C. Some oxidation tests were also performed at 1375{degrees}C. Coated material was prepared for contact stress testing at 1000{degrees}C and 1200{degrees}C. Results indicate that with the present coating configuration, potential exists for commercial application at temperatures of up to 1200{degrees}C. Increases in the use temperature appear possible by modifying the coating properties.

• Research Organization: Oak Ridge National Lab., TN (United States); GTE Labs., Inc., Waltham, MA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 10175404
• Report Number(s): ORNL/Sub--86-95915/1; ON: DE92041373
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104
33 ADVANCED PROPULSION SYSTEMS
330100
36 MATERIALS SCIENCE
360201
360203
BONDING
CERAMICS
CHEMICAL VAPOR DEPOSITION
COATINGS
COMPONENTS
HEAT ENGINES
HOT PRESSING
INTERNAL COMBUSTION ENGINES
MATERIALS
MECHANICAL PROPERTIES
OXIDATION
PREPARATION AND FABRICATION
PROGRESS REPORT
SILICON CARBIDES
SILICON NITRIDES
SINTERING
STRESSES