A Surface Texturing Approach for Cleaner Disc Brakes

Abstract

Brake dust generated in vehicle brakes causes discoloration of wheels and, more importantly, the emission of particles suspected of health hazard in the environment. Laboratory testing of brake pad materials against cast iron discs revealed that the majority of wear particles are submicrometer in size. Wear particles with a size of 350 nm had the highest percentage in the particle size distribution plots, regardless of the magnitude of the nominal contact pressure and the sliding speed. Due to their predominantly submicrometer size, a significant amount of brake dust particles may be inhalable in environmental and occupational exposure situations. In order to prevent the dispersion of particles into surrounding environments, a surface topography design with radial microgrooves on the disc was utilized to trap wear particles immediately after their formation. The particles moved radially outward in the microgrooves due to the centrifugal force and were collected in a reservoir. The design yielded a cleaner pad/disc test setup, a smoother friction coefficient plot, and a reduced wear volume. The steady-state friction coefficient remained the same as the one obtained from the control samples with a non-modified design. Presented at the ASME/STLE Tribology Conference in Logn Beach, California October 24-27, 2004 Review led by Roger Melley