Study on Grinding Mechanism of Brake Pad with Copper Matrix Composites for High-Speed Train

Abstract

e processing mechanism of copper matrix composites is very complex, for the particle phase and lubricating phase are randomly distributed in the copper matrix phase, and the characteristics of the three phases are completely different. Aiming at understanding the chip formation and the influence of each phase of the material on the workpiece surface morphology, a single abrasive grain cutting experiment is carried out. Experiment results show that the cutting force increases with the increase in the cutting depth, but the increase amplitude is smaller. Extrusion of the abrasive particles causes plastic deformation of the copper matrix phase and brittle fracture of the particle phase and graphite phase. It results in the defects on the groove surface, such as pits, collapses and cracks, and holes. e brittle fracture of the graphite phase and the breaking and falling off of the particle phase block the plastic deformation of the copper alloy, which makes the copper alloy not forming ductile chips. e chip is mainly powdery. It shows that the brittle fracture is the main removal form of the brake pad material. e copper matrix phase on the surface of the groove produces obvious plastic deformation. e plastic deformation at the bottom is larger and has a certain degree of fibrosis appearing.

Investigation on Speed-Load Sensitivity to Tribological Properties of Copper Metal Matrix Composites for Braking Application

“…The morphologies of the worn surface and subsurface created during braking are very important for the identification and development of wear mechanisms, as they can provide valuable information about the nature of wear, and the effects of braking parameters and environmental conditions on tribological properties [12,13]. In recent years, importance has been given to the structures of the worn surface and subsurface of brake friction materials.…”