Braking pad-disc system: Wear mechanisms and formation of wear fragments

The tribological phenomena that occur in brake systems are interesting even in other respects than just the braking action. One important issue, that is gaining increasing importance over the last years, concerns the environmental impact of wear debris produced by the braking action. In this context, the present study is focussed on the tribological behaviour of a commercial friction pad material dry sliding against a cast iron disc. Pin-on-disc tests were conducted at room temperature under mild wear conditions, as concerns load and rotating speed. The effect of some components of pad material, in particular of copper, on the dynamic of formation of tribological layer and wear debris is presented. The results obtained so, although referring to quite a simpler system that real brake systems, still may provide interesting indications, for instance in view of the development of novel brake pad materials and braking control systems. (C) 2014 Elsevier B.V. All rights reserved.