FEASIBILITY DEMONSTRATION OF PYROLYTIC GRAPHITE COATED NOZZLES
Abstract
The objective of this program is to demonstrate the feasibility of pyrolytic graphite coatings for use in uncooled solid propellant rocket nozzles (in a size range of use for practical propulsion units) under very severe operating conditions. In prior work, the excellent serviceability of pyrolytic graphite coatings in 1/2-inch diameter nozzles was demonstrated with propellants having flame temperatures from 5500F to 6500F. In current work, nozzles of 1.1- inch and 2.3-inch diameter are to be tested with a 6550F propellant. This report describes the work of the third quarter of this program. Improvements were made in preparing crack-free sub-scale coated inserts. Flaw-free coatings as thick as 54 mils were prepared. Application of this improved art to full- scale inserts is underway. Stress analysis indicated the merit of alternate substrate materials and deposition work with these is underway. A successful 35-second sub-scale firing was made but during a 60-second firing discrete coating losses were observed. In the first full-scale motor firing excessive erosion was observed from a coating containing a known separation. This behavior was analogous to early sub-scale experience.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 25, 1964
- Accession Number
- AD0608721
Entities
People
- James D. Batchelor
Organizations
- ARCO