CMC Materials for Lightweight and Low CTE Applications

Carbon fibre reinforced CMC materials, originally developed for the thermal protection of reusable spacecrafts, offer a great applicability for extreme lightweight and thin walled structures combining an excellent strength to density ratio with a close to zero thermal expansion behaviour. These outstanding properties and a cost efficient manufacturing route, predestine these C/C-SiC materials for a variety of low CTE applications e.g. for telescopes or calibration artefacts. This paper deals with principal correlations between the thermal expansion of different C/C-SiC materials as well as their microstructural characterisation. Additionally, two special applications designed, manufactured and tested successfully in collaboration with industrial partners will be described exemplarily. One is a telescope structure for the data link between satellites based on an optical concept. The other application is a new calibration ball plate for coordinate measuring machines.