Ceramic brake discs made out of short fibre reinforced C/SiC material show exceptional tribological properties and outstanding wear characteristics. However, the high price of these ceramic brake discs prohibit a broader use. Therefore, a new approach for a lightweight metal-ceramic hybrid brake disc, which consists of an aluminium support disc lined with short fibre reinforced C/SiC ceramic segments, is presented. Aluminium is used for the supporting body due to its low density, high thermal conductivity, corrosion resistance and low cost. The ceramic segments are used for the friction surface of the hybrid brake disc as a result of their favourable tribological and wear properties. An overview is given on the potential application areas and on the construction, manufacturing and testing of said hybrid brake disc.
A potential use case of a mid-class sedan with a mass of around 1.8 t and maximum travelling speeds of up to 200 km/h is taken as a basis for the construction of the hybrid brake disc. The dimensioning of the brake disc was conducted with the aid of thermal finite element analysis methods, so that the critical temperatures at the joints stay within predefined boundaries, which are determined by joining methods and material properties. Furthermore, different joining methods are examined and benchmarked in the light of the use case. Hence a Prototype brake disc was manufactured and tested on the dynamometer of the University of Bayreuth where different characteristic values, like wear, coefficient of friction and different temperatures were measured. The results were then compared to the results of standard commercially available brake discs, which were also measured on the dynamometer. In addition, the material properties of the used short fibre reinforced C/SiC were determined by three-point bending tests and microstructural analysis.