Full-ceramic brake systems for high performance friction applications

Ceramic matrix composites (CMC) are promising materials for friction applications. Typically, C/SiC rotors are combined with organic pads (Low Met). Within this work, two types of CMC brake pads were studied, C/SiC SF as well as C/SiC SF 11Coke with 11vol.% coke as filler, accompanied with the Low Met reference pads. Small brake pads (400mm2) were applied on a lab-scale and larger pads (12,000mm2) on a full-scale inertia dynamometer. In both cases, the corresponding rotor was a C/SiC disc with a SiC-rich friction layer. Sliding speeds up to 42.6m/s and braking pressures up to 8MPa were applied. The smaller CMC pads show lower wear and higher coefficient of frictions (COF), compared to the reference. This frictional behavior was confirmed on the full-scale dynamometer with mean COFs up to 0.45. However, the wear of the large C/SiC pads was somewhat higher on the full-scale dynamometer.