Tribological behavior and mechanism of h-BN modified copper metal matrix composites paired with C/C–SiC

Abstract

Abstract The thermal stability of hexagonal boron nitride (h-BN) plays a crucial role in stabilizing the braking performance of friction pairs (i.e., brake-pad/disc) in high-speed trains. In this study, h-BN modified copper metal matrix composites (Cu-MMCs) were fabricated via powder metallurgy, and their tribological behavior and mechanism upon pairing with C/C–SiC were investigated. Results show that as the h-BN content increased, the wear mechanism of the Cu-MMCs switched from abrasive to severe fatigue, followed by switching from mild oxidation to adhesive abrasion. Additionally, Cu-MMCs containing 2\xa0wt% h-BN exhibited a high, stable coefficient of friction (COF) during repeated high-speed braking cycles together with a smoothed braking process at high braking speeds.