The Size Effect of SiO 2 Particles on Friction Mechanisms of a Composite Friction Material

In this paper, the effect of SiO 2 particle size on friction mechanisms was investigated. Five different size scales (10 µm, 80 µm, 180–700 µm, 700 µm–2.0 mm, and 3.0 mm) were selected to prepare non-commercial friction materials. Friction testing for these materials was conducted on a pad-on-disc-type friction tester under certain conditions. In order to identify the friction behaviour during the friction process, worn surfaces after test were observed using SEM. Results revealed that the friction mechanisms changed with particle size. In addition, a simple physical model was developed to provide quantitative analysis for the friction coefficient of materials containing large particles. Further, the predictability of this model was investigated across a range of formulations and controlling factors.