The environmental impact of the braking systems of different vehicles has become a topic of interest for the public. With Euro 6 emission limits the particulate matter emissions of standard brake systems are comparable to the particle matter emissions of internal combustion engines which further expedites the public attention. Therefore, the reduction of the particle matter emissions of brake systems is vital not only for electric vehicles. Three different brake pads were tested on four different brake discs (grey cast iron, carbon ceramic, Al-MMC, metal-ceramic hybrid). A LowMet brake pad was used as a benchmark, state of the art brake pad material. Furthermore, a short fibre reinforced C/SiC brake pad which was modified with petrol coke and SiC powder and manufactured using the liquid silicon infiltration process as well as a fabric reinforced C/C brake pad manufactured using chemical vapour infiltration were investigated. The tribological tests were conducted using an adapted Auto-Motor-Sport-Test. All friction pairings were characterized using 10 consecutive stop brakings (each ≈ 0.5 MJ) and three different braking pressures (1, 2, 3 MPa). The corresponding friction coefficients were recorded as well as the wear rates of the brake pads. For a deeper understanding of the measured tribological characteristics of the friction pairings, the friction surfaces of the used brake pads were characterized using secondary electron microscopy.
University of Bayreuth: Mr. Thorsten Opel, Dr Nico Langhof, Prof. Dr-ing. Walter Krenkel, Prof. Dr.-Ing Stefan Schafföner