Metallic and ceramic matrix composites can be used up to several thousand degrees Celsius. Still, there is great interest in using polymeric composites in high-temperature applications because of their lighter weight, better fatigue properties and ductility. Such materials can have a positive impact on the weight of aircraft engines and, therefore, on fuel consumption and carbon dioxide emissions. The EU-funded project HICTAC (High performance composites for demanding high temperature applications) addressed these challenges through the development of a durable polyimide resin, together with the required manufacturing technologies. The new material exhibits not only high performance but also processing characteristics suitable for carbon fibre-reinforced composite components. Research was focused on the formulation of a thermosetting polyimide tailored for resin transfer moulding of composite parts for the aerospace industry. A major challenge was to adjust the formulation that ensures softening temperatures above 360 degrees Celsius, sufficiently low melt viscosity and appropriate curing characteristics. HICTAC partners were successful in their efforts. The developed resin and improved resin transfer moulding were used to prepare laminates and coupons for large components with blade-like geometry. Extensive mechanical and thermal testing under various temperatures and oxidative ageing confirmed the demonstrators' high quality and few manufacturing-induced defects. The new easy-to-process resin for use in high-temperature applications is already available on the market under the tradename NEXIMID® MHT-R. Although initially designed for composite parts for the aerospace industry, the machine manufacturing industry and transport sectors will also benefit where replacement of metallic parts exposed to high temperatures is possible. The HICTAC project has resulted in a unique alternative to metallic and ceramic composites, establishing a leadership position for the EU in what promises to be a lucrative global market.
High-temperature, composites, aero engines, HICTAC, polyimide, resin transfer moulding