Mechanisch hoch-belastbare thermische Barriere-Beschichtungen mit Oxidationsschutz für Kohlefaser-Verbundwerkstoffe
Joanneum Research, Austria
AAC, SECAR (Austria), BVT Beschichtungs- und Verschleißtechnik GmbH, Materials Center Leoben Forschung
Carbon fibre composites are optimal light-weight design materials for aerospace and automotive applications, but are limited to temperatures of 350°C (polymer matrix) due to polymer degradation and creep, and 450°C (silicate matrix) due to carbon fibre oxidation. However, future use in turbo-fan compressors in aircrafts as well as in mobile small combustion engines require 500°C operation temperature with 200 MPa fatigue limit and 900°C short-time peak temperature limit, being the goals of the material development in the project. Since SiC fibres cannot be used in combination with the easy high-duty processable silicate matrix due to low ductility and elasticity, thermal and oxidation protection of carbon fibres must be ensured by the development of an innovative cost-effective surface coating of the composite by plasma spraying of barrier layers (TBCs), sol-gel processes for sealing and smoothing the TBCs and top coating for infrared-radiation reflection.