Investigation of Ceramics for High Temperature Turbine Vanes.
Abstract
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1972
- Accession Number
- AD0742857
Entities
People
- Svante Prochazka
Organizations
- General Electric