TRIBOLOGICAL PROPERTIES OF BRAKE DISCS COATED WITH Cr2O3–40% TiO2 BY PLASMA SPRAYING

摘要

In this study, the tribological properties of Cr2O3–40% TiO2 coating for brake disc materials were investigated in braking performances. Plasma spraying technique was used in order to deposit coating materials onto cast iron disc with ventilation channels substrate. The braking performances of discs were tested according to SAE J2430 test standard. Microstructures of discs were characterized by means of light microscope (LM), scanning electron microscope (SEM) and energy-dispersive spectrometry (EDS). The surface hardness and roughness were measured with testers. In general, it is noted from the LM and SEM images that there was an infinite gradation between coating layer, binding material and the lamellar graphite cast iron and that bonding resistance was excellent. The coated disc exhibited less wear, approximately the same coefficient of friction and longer life than the uncoated disc. As a result, the coated disc could be a much better alternative for new-generation brake discs in the motor vehicles than the uncoated disc.