||Glass fibers constitute a good candidate for brake-lining performance improvement. Their contribution is investigated within a reduced formulation, based on a limited number of components, specifically developed and efficient in braking situations.
Friction and wear mechanisms and tribological behavior are analyzed in relation with the composite microstructure as well as material properties, considering two different braking-test protocols designed with regard to brake-induced thermal loadings. Infrared thermography is used to monitor thermal phenomena occurring during braking tests.
It is shown that addition of glass fibers, in the form of bundles containing tens of fibers, increases thermal properties, enhances normal-compression modulus and allows decreasing wear. Fibers orientation appears to be a key factor with regard to the load-bearing mechanisms, allowing the development of a compacted third body at the rubbing interface when oriented normal to the surface. Conversely, fibers oriented in the sliding plane emerge from the rubbed surface and are not able to improve the load-bearing capacity. Addition of glass fibers helps to reduce thermal localizations, in consistence with higher thermal effusivity allowing better heat absorption and higher normal compressive modulus reducing the anisotropy and improving the pressure distribution.