Effect of Nitrile Butadiene Rubber (NBR) on Mechanical and Tribological Properties of Composite Friction Brakes

Abstract

The aim of this research is to investigate the effect of nitrile butadiene rubber (NBR) as fillers on the mechanical and tribological properties of composite friction brake. Four compositions of specimens, having different NBR volume fractions (0, 4, 8, and 12 %), were manufactured. We assessed their mechanical properties by the three-point bending method according to ASTM D790 standard. We measured their tribological properties under various contact pressures and sliding speeds using a pin on disc tribometer. The results showed that NBR could improve the mechanical properties of composite friction brake materials, and the tribological properties such as wear resistance and friction coefficient increased with increasing NBR volume fraction.

Wear Studies on Phenolic Brake-Pads Using Taguchi Technique

“…Trapped and compressed wear debris particles between contacting surfaces under heat forming contact plateau [23]. It suggests that contact plateaus are formed mainly by phenolic resin binder, which have been compacted during friction.…”

Full-scale dynamometer tests of composite railway brake shoes including latxa sheep wool fibers

“…First, a pre-mix was produced by mixing typical raw materials to be found in brake compositions. These raw materials included nitrile butadiene rubber (NBR, that can improve the mechanical properties of composite friction materials, as well as wear resistance, friction coefficient and damping braking noise (Fei et al, 2015;Surojo et al, 2019), steel fiber (the most widely used metallic fibers in friction materials, Kalel et al, 2021, can have effect in both the friction performance and wear of the friction material in which it is used, Matějka et al, 2009), barites (a very common filler, Kumar and Kumar, 2020, that is important in the formation of a stable transition layer, Menapace et al, 2018, and substantially influences the friction coefficient and specific wear ratio, Sugözü and Daghan, 2016), magnesium oxide (a soft abrasive which can serve as a wear reducing filler when in presence of more aggressive abrasives and can act as an accelerator, speeding up the rubber vulcanization, Singh et al, 2020) or zircon (an abrasive that can lead to heat resistance at elevated temperatures, Park et al, 2021), affect the friction stability depending on its particle size and modify the friction material wear rate, Shin et al), among others (Monreal et al, 2021a). These constituents were mixed for 2 min in a laboratory-scale powder disperser, which comprised of a cylindrical steel container with four spinning blades at its bottom.…”