Research and Development of Ceramic Turbine Wheels

The bending strength of specimens of various sizes, some of which were cut from a turbine wheel, was compared with predictions using Weibull statistical theory. The stress distribution of a ceramic turbine wheel in spin testing was determined with finite elements and the results were used to analyze a wheel that was spun until it burst. The cause of the burst of the ceramic radial turbine wheel at elevated temperature is discussed and based on the tensile rupture data. A design methodology using the Larson-Miller parameter was found to be applicable to the ceramic components at elevated temperatures.