Impact of brass contents on thermal, friction and wear properties of brake linings composites

Automotive brake lining materials are composite materials of very complex formulation, highly heterogeneous. They help to carry out the desired combination of braking performance properties. Obviously, it requires that the friction material exhibits good complementarities and adequate combination of physico-chemical, thermal properties that act synergistically to provide the braking performance which should be adjusted by the addition of metallic fillers. The aim of this work is to study the role of one of the copper alloy particles, namely brass, on friction and wear. For this purpose, the experimental approach is based on the development of a simplified formulation. Three derived composites were developed in the laboratory by the addition 1.5 wt.%, 3 wt.% and 4.5 wt.% of brass. It is shown that addition of copper alloy particles increased thermal properties. Wear test results show that brass contributes to friction and wear mechanisms from a quantity introduced in the formulation equal to 4.5 wt.%. In fact, given its large size, it acts as primary plates serving as supports for the formation and expansion of plates necessary to enhance the stability of friction coefficient. Conversely, when adding an amount less than 4.5%, brass particles are generally all removed from the matrix implying a higher source flow of third-body wear.