C/C-Sic Composites for Hot Structures and Advanced Friction Systems

Originally, the demands in space technology played the decisive role in the DLR's development of melt-infiltrated ceramic matrix composite (C/C-SiC) materials. High mass-specific characteristics and extreme temperature resistance are important selection criteria for materials used in jet engines and thermal protection systems in new spacecraft and rockets. Within the last few years, the properties and the manufacturing methods of C/C-SiC materials were consistently improved, so that particularly the brake industry can now share the profits of this new class of material. Brake disks and pads made of C/C-SiC offer great advantages for high performance vehicles as well as emergency brake systems. Mainly based on carbon and silicon carbide these braking materials show high and stable coefficients of friction and low wear rates. Prototypes of originally sized pads as well as disks have been manufactured and were sucessfully tested by the respective brake system manufacturers or end-users. After seven years of development, C/C-SiC braking materials are now entering the market in high performance cars, trains, and lifts. Their main advantages lie in the reduced mass, their non-fading characteristics, their improved coefficient of friction, and their extremely low wear rates.