To make the most efficient use of silicon nitride and silicon carbide at temperatures of 1400 and 1600C, there is a need to understand the steady stress and dynamic stress (mechanical and thermal) durability together with particularly debilitating environments such as corrosion.
This research achieved its goal of developing, producing and testing silicon based ceramics. Further testing will be conducted to validate the developed materials.
Production facilities were created for the production of silicon carbide and silicon nitride materials. A European facility was developed for the assessment of creep using axial, tensile, and constant stress loading. Further developments and industrialization of the materials as components in gas turbine engines are planned.
The use of ceramic materials in gas turbines can improve fuel consumption and power output considerably. This is achieved by more efficient gas path, partly as a result of the dimensional stability of ceramics and also by the reduction or elimination of expensive cooling air. The ceramic turbine components must then operate at extremely high temperatures for prolonged periods. Thus at the design stage, data will be needed to precisely define the creep and creep fracture characteristics of the relevant ceramics. Moreover, there will be problems due to component oxidation, exarcerbated by possible contaminants in the service atmosphere. With the help of a new approach to creep data acquisition and analysis it may be possible to reduce the time scales and expenses of conventional test programmes. The work carried out is focused on creep behaviour and creep life prediction, thermo-mechanical fatigue life, the effects of marine environment, the microstructural behaviour and the use of certain ion assisted processes to produce protective coatings.