Effects of Fe and graphite on friction and wear properties of brake friction materials for high-speed and heavy-duty vehicles

In this study, the powder metallurgy process was used to prepare friction materials. Fe and graphite powders were added to the friction materials at different proportions. The friction and wear properties of the materials were evaluated by the MM3000 friction and wear tester. Combined with scanning electron microscope and physical and mechanical properties testing, the influence of the synergistic effect of Fe powder and graphite on the properties of the friction materials was studied. The results showed that the total content of Fe and graphite has not changed. Moreover, the hardness and strength of the material increased by increasing the iron content. The average friction coefficient first increased and then decreased. Furthermore, the instantaneous friction coefficient stability decreased, and the wear extent first slightly decreased and then increased. The comprehensive properties of the material were optimal when the Fe content and graphite powder were 14 % and 20 %, respectively.