Hot Isostatic Pressing of Shaped Silicon Nitride Parts
Metallic materials have for a long time been essentially the only choice of designers for applications where high strength and longtime stability at elevated temperature have been required. Attempts were made about 25 years ago to use oxide ceramics for gas turbines but ended in failure mainly because of their sensitivity to thermal shock, which is typical of this type of material. The interest in the use of special ceramics as a structural material has increased greatly during the last few years and one of the most promising materials for highly stressed parts is silicon nitride, Si3N4. One application which particularly stimulates the development of better material properties and fabrication techniques for this material is its potential use in ceramic gas turbines for vehicles. A ceramic gas turbine for a vehicle with uncooled vanes and turbine blades operating at temperatures up to 1350°C could meet the very strict demands for low emissions. In addition, it would be compact, of low weight, and be superior to even the diesel engine in fuel economy.
KeywordsSilicon Nitride Turbine Blade Rupture Strength Reaction Bonding Silicon Nitride Powder
Unable to display preview. Download preview PDF.