Completed funded project

Silicon carbide fibres can be used at higher temperatures than oxide ceramic or glass fibres and have better oxidation resistance than carbon fibres. As a reinforcing component in ceramic composite materials (SiC/SiC-CMC) they are of great importance. The production of high-temperature stable SiC fibres is still based exclusively on the synthesis of expensive polycarbosilanes. The high fibre costs prevent a broad application. Furthermore, SiC fibres are only produced by a few companies in Japan or the USA, and access to the fibres by European companies is very limited.

In a joint project between the companies BJS Ceramics, MTU Aero Engines and the Fraunhofer Centre HTL, a high-quality SiC fibre was to be developed to enable European fibre production. The fibre used a polysilane-polycarbosilane as the starting material, which had the potential to reduce costs. The project aimed at scaling up all production steps to a maturity level of at least TRL 4. It should also demonstrate on laboratory scale that SiC fibres can be converted from Generation 2 fibres to Generation 3 fibres by chemical and thermal processes.

• New polymer synthesis route without nitrogen input; pure polysilane (TRL 3-4)
  
• Production of reproducible spinning masses on a kg scale (TRL 4)
• Reproducible spinning fo polymer solutions into endless green fibre bundles > 200 m length (TRL 4)
• Optimisation of the pyrolysis of green fibres to ceramic fibres with stoichiometric Si:C ratio (TRL 4)
  
• Coating of the fibres for corrosion protection and matrix bonding (TRL 4)
• Further processing of the coated  SiC fibres to CMCs with CVI matrix test of the SiC/SiC-CMC