Investigation of PG/SiC Processing Variables.
Abstract
This report describes a program conducted to investigate the relationships between process conditions and Pg/SiC codeposit coating characteristics. The work was directed primarily toward the investigation of conditions other than those routinely used to coat test components for other programs. The program involved two areas of study: (1) reduced (subatmospheric) pressure codeposition and (2) gas flow characteristics in atmospheric pressure furnaces used to coat large nozzle components. The deposition study involved the conduct of a series of experimental runs in order to establish conditions which produced an acicular SiC structure in the codeposit. A final run was conducted in an attempt to apply a coating with this microstructure to a contoured surface which simulated a subscale nosecap. The flow study involved the construction and operation of a 2D water analog of large deposition furnaces. The analog was used to simulate flow patterns in furnace assemblies then in use to coat nosecaps and throat inserts for 7.0 inch nozzles. The SiC structure is dependent upon pressure, but an acicular SiC structure can be achieved at reduced pressure. Further, acceptable deposition rates can be achieved at reduced pressure. Generally, smooth coatings result and the bond with the substrate material (ATJ graphite) is strong.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 30, 1977
- Accession Number
- ADA041047
Entities
People
- C. W. Newquist
- J. P. Copeland
- R. S. Valentine
Organizations
- ARCO