Garrett Experience in Ceramic Turbocharger Turbine Wheels

Technical ceramics have generated a great deal of interest for turbocharger turbine wheels in recent years because of light weight and excellent high temperature strength. The properties of commercially available silicon nitride compositions and the ways in which they influence the design of turbine wheels are discussed. Methods of attaching ceramic wheels to metal components are reviewed, and the statistical treatment of probability of fracture is outlined. Garrett experience in vehicle testing of ceramic turbine wheels is presented, as well as recent data relating to drivability under conditions of part-throttle acceleration.