Investigation of Ceramics for High Temperature Turbine Vanes.
Abstract
The lower limit of boron addition to bring about the highest degree of densification in submicron SiC containing 0.5% excess carbon is 0.3% B. At this boron level the majority is in solid solution after sintering. Other elements when added in small amounts have little effect, amounts of 1% or more impede densification. The beta to alpha transformation in SiC during sintering is nucleation controlled. Thermal expansion, heat conductivity, elastic moduli, fracture energy, MOR, Weibull modulus and oxidation resistance for sintered SiC are reported. A development of tensile strength measurement technique based on the theta ring test is discussed. A technique for studying the effect of sintering variables such as temperature, time, atmosphere, etc., based on computerized monitoring of shrinkage during sintering, is used for optimization of firing conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 25, 1974
- Accession Number
- ADA005830
Entities
People
- Curtis A. Johnson
- Robert A. Giddings
- Svante Prochazka
Organizations
- General Electric