Abstract
KEYWORDS – PM10 emissions, low-metallic brake pads, dyno-bench testing, COF stability, surface characterization.
ABSTRACT
Two pairs of low-metallic brake pads (BP1 and BP2) with different chemical composition as measured using wave dispersive X-ray fluorescence spectroscopy were selected for this study. The brake pads were tested with an inertia brake dynamometer adapted for isokinetic sampling of PM10 wear particles. A modified SAE J2707 (part B) testing procedure was used for both tests. PM10 particles released during brake stops were captured under isokinetic conditions on a 47mm quartz filter, while particles larger than 10 micron were removed by a PM10 cyclone. The character of the brake pad friction surface was studied using scanning electron microscopy. It was observed that COF of sample BP1 increases during the individual brake events from approx. 0.4 to 0.7; while the COF obtained for BP2 shows a steady value approx. 0.4 during individual brake stops. The average PM10 concentration in the given experimental set-up reached a value of 1.47 and 0.56 mg/m3 for sample BP1 and BP2, respectively.