Investigation of Ceramics for High Temperature Turbine Vanes.
Final rept. 1 Apr 71-31 Mar 72,
GENERAL ELECTRIC CORPORATE RESEARCH AND DEVELOPMENT SCHENECTADY N Y
Pagination or Media Count:
Hot-pressing of a 99.7 pure commercial silicon carbide powder with one percent boron addition has yielded a 99 dense ceramic with 30 microns tabular grains and 50,000 psi flexural strength. A submicron particle size powder consolidated with 1 boron addition at 1950C gives 108,000 psi strength at room temperature and 64,000 psi at 1500C. Its microstructure is composed of 3.0 microns equiaxed SiC grains and less than 0.5 of free silicon forming isolated grains at the lower temperature and a grain boundary phase and intragranular inclusions at 2100C. No boron containing phase could be detected. The structure is formed by a mixture of various hexagonal poly types with the alpha-6H form prevailing. Author
- Coatings, Colorants and Finishes
- Jet and Gas Turbine Engines