Previous research has highlighted that the formation of a sustained friction film, desired for stable and predictable friction performance, is highly dependent upon the region of the substrate (CMC) being examined. In attempt to improve the friction performance, notably bedding-in, research at LU has been developing coatings aimed at ensuring friction film development across the substrate. This paper focuses on the performance of one of these coating formulations, and examines the performance of this on a laboratory scale dynamometer. Subsequently, the coating has then been applied to a full size brake disc, as used on a prestige vehicle, for dynamometer testing at an industry scale for comparative purposes.
On both lab and full scale samples the bedding performance shows improvements over the standard material, and at the full scale the coating indicates improved stability of subsequent friction performance through a modified AK Master test schedule. Post-test OM and SEM characterization of the friction surfaces shows that friction film formation has improved over the standard samples, and EDS elemental analysis indicates the presence of the original coating remaining within the formed friction film.
Further characterization of the friction surface aims to identify the interactions between the coating and the substrate before and after friction testing.