Wear of Single and Multilayer PVD Coatings on CFRP in Erosive Environments

Kurzfassung

Carbon fibre reinforced plastics (CFRP) are of great interest in aerospace industries due to its high strength to weight ratio. The portion of fibre reinforced polymers in modern airplanes is growing fast in order to reduce the overall weight and to increase fuel efficiency. However, the use of CFRP is limited by its poor wear resistance, similar to other polymer materials. Especially erosion caused by sand, dust and rain can result in heavy damage on CFRP components. In this work CFRP is coated by magnetron sputtering to improve its erosion resistance. A wide variety of wear protection coatings can be realized by magnetron sputtering and the possibility to reach process temperatures below 100°C allows the protection of temperature sensitive materials such as polymers. CFRP was first coated with three different single layer coatings (Titanium, Aluminium and Ti6242). In addition, hard coatings like TiN and TiB2 were successfully sputtered at low temperatures onto the substrates. Ti/TiN multilayer systems with two different layer thicknesses were also deposited to combine hardness and ductility of both materials. In situ plasma pre-treatment in a mixed argon/ oxygen atmosphere provided good adhesions of all coatings to the polymer substrates. The coatings were analysed in SEM, and their hardness, roughness, and erosion resistance were measured. The weight loss during erosion could be reduced by the titanium single layer coating and a Ti/TiN multilayer system, suggesting both coating systems are promising candidates to improve the erosion behaviour of CFRP.