Dip Process Thermal Barrier Coatings for Superalloys.
Abstract
A new technique of developing thermal-barrier coatings for superalloys has been investigated. It involves hot dipping of superalloys samples into a molten bath of low melting Ce-Co or Ce-Ni alloy. By internally oxidizing these coatings, it is possible to obtain a duplex with a CeO2-rich oxide scale as the outer layer (thermal barrier) and in inner layer composite of fine cerium oxide particles dispersed in a matrix of Ni(Co)CrAl. This inner layer, or subscale, grades into the superalloy. Appropriate heat treatment can produce recrystallized CeO2 particles in the subscale that should improve adherence of the oxide scale to the subscale and substrate superalloy. The coating process does involve limited reaction between the coating alloy and superalloy. The thickness of this interaction zone can be controlled and compensated for in the design (cross section) of the superalloy component. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1980
- Accession Number
- ADA088064
Entities
People
- G. N. Krishnan
- I. M. Allam
- R. W. Bartlett
Organizations
- SRI International