A TEM snapshot of magnetite formation in brakes: The role of the disc's cast iron graphite lamellae in third body formation

▶ Exfoliation from cast iron graphite flakes due to shear forces. ▶ Mechanical action of graphene in cast iron due to external friction force. ▶ High oxidation rate of iron nano-particles. ▶ Friction film nano-texture due to graphene insertion in compliant iron matrix.