The reduction of exhaust emissions resulted in other emission sources becoming the focus of public interest. Brakes and tyres were identified as the main emitters in vehicles with new exhaust standards. Compared to tyres, brakes have a higher hazard potential due to the chemical compositions and the high-temperature processes combined with the emissions of ultra-fine particles in the boundary layer. The investigation of brake emissions is mostly carried out in enclosed and controlled test environments, where both the concentration and the size spectrum of individual applications are analysed. For the most part, dynamometer is used, where only a limited amount of information can be obtained on the correlation between wear, emissions, surface signatures and friction parameters during brake applications. For the basic investigations of the characteristics of the contact between brake disc and brake pad, mainly pin-on-disc test benches, are used. For this purpose, the Automated Universal Tribotester (AUT) is used at the Institute for Dynamics and Vibration (IDS), which, in addition to recording the friction parameters such as the coefficient of friction, has quasi in-situ measurement options for the surfaces. In addition to determining the wear behaviour, surface properties such as roughness parameters can also be determined. The aim of this work is to investigate the influence of surface properties, in particular of various roughness parameters, on the emission behaviour of individual brake pairings. The basis for this is the interaction between the occurrence of holes (reservoirs) and patches, the so-called Surface Reservoir Dynamic. It was observed that the emission characteristics change significantly with the number of reservoirs and the degree of filling of the reservoirs associated with low roughness.

TU Braunschweig: Mr. Malte Sandgaard, Prof. Dr.-Ing. Georg-Peter Ostermeyer