Damage mechanism of Fe-based powder metallurgy friction materials in high energy braking

Fe-based powder metallurgy friction materials were prepared by powder metallurgy pressure sintering technology, and the damage mechanism of the friction materials under the high energy braking conditions as the speed of 7500 r·min⁻¹, the surface pressure of 0.8 MPa, and the inertia moment of 0.045 kg·m² was studied. The results show that, the damage and failure of the Fe-based powder metallurgy layers are mainly graphite shedding and surface crack. The initiation of surface thermal cracks is mainly distributed at the interface between the matrix and graphite phase and at the sharp corners of the edge shedding. The existence of micro-cracks reduces the energy of the main crack propagation, hinders the main crack propagation, and plays a role in improving the performance stability of the friction parts.