Non-exhaust particle emissions in road transport relate to the wear process of varied vehicle components such as tyre-road interaction, clutch wear and brake wear. Non-exhaust emissions represent up to 50% of the total PM10 emissions generated from road transport. About 50% of the non-exhaust emissions come from the brake system. In Euro 7, non-exhaust emissions will be, for the first time, regulated along with exhaust emissions. This project will develop novel coatings on traditional brake discs to reduce particle emissions. The coatings can not only be used to produce new brake discs, but also be applied to refurbish worn out waste brake discs. In the latter case, a circular economy will be naturally formed by reusing 'waste' materials. The coating powder materials mainly consist of 316L stainless steel as the matrix and are reinforced with varied hard phase powders (i.e. WC, TiC, SiC, Mo2C and Cr3C2) in different contents and size ranges. A Nanovea® T50 tribometer will be employed to simulate the brake contact between the brake pads and discs. Coefficient of friction and wear mass loss will be determined in this process. Meanwhile, the emitted particle mobility size distributions and number concentrations will be measured using a mini wide-range aerosol spectrometer (GRIMM® MiniWRAS Model 1371). The MiniWRAS measures particles ranging from 10 nm to 35 μm at 41 size channels. It will give a precise information about PM10, PM2.5, PM1 and particle size distribution. A cascade impactor will also be used in this step to collect emitted particles on different sizes. The collected particles will be characterized regarding the morphology and chemical composition. An environmental scanning electron microscopy (ESEM) equipped with energy-dispersive X-ray spectroscopy (EDXS) will be employed to characterize the particles. The results will facilitate the development of new brake disc materials to replace the gray cast iron disc, which has relatively low wear resistance and corrosion resistance, at the same time reducing airborne brake emissions.

Dr. Yezhe Lyu, Assistant Professor, Lund University; Dr. Christina Windmark, Assistant Professor, Lund University; Dr. Lucia Lattanzi, Postdoctoral Fellow, Jönköping University; Dr. Samuel Awe, Expert Research Engineer, AC Floby; Prof. Jens Wahlström, Chair Professor, Lund University