Development of protecting coatings for composites in an aero-engine

Carbon fibre reinforced polymer (CFRP) composite materials exhibit high specificstrength and stiffness therefore they can be a lightweight alternative to metalliccomponents for the front section of an aero-engine. Despite the benefit of CFRP composite materials for aero-engine applications, there arealso new challenges due to their inherent properties compared to conventionalaerospace metallic structures, such as a lower erosion resistance, poor thermalresistance, and poor electrical conductivity. In aero-engines, some components can be subjected to harsh erosive environmentsduring operation, therefore the erosion resistance of CFRP composite materials need tobe investigated. CFRP composites are not able to withstand as high temperatures astraditional metallic components and their ability to resist fire events need to beenhanced. On the other side, the poor electrical conductivity of CFRP composites canalso be critical when the aircraft is struck by lightning. Therefore, improving theconductivity of CFRP composite is of large interest. This thesis work is focusing on investigating innovative coating solutions to overcomethese three independent challenges in order to enhance CFRP composite applicationsinto the front section of an aero-engine. Coating systems for lightning strike protection have been investigated and developed.A fire protection has been identified and tested; the tests showed promising results forfire application. Furthermore, investigations on erosion resistant coatings indicated thepossible improvement of replacing the currently used erosion resistant coating by othercoatings presented in this thesis work