Dry friction behavior of NiCrBSi-%35W2C coated brake disks

Abstract

Abstract For speeding up motor vehicles, new brake disk materials with higher frictional need to be developed. Brake disks work under very difficult thermomechanical conditions due to high temperature and wear. As most of commercial disks have high wear rate and low braking performance, there is a need for development and manufacturing of new disks-brake linings to reduce wear and to increase braking performance in motor vehicles. Ceramic coated disks have shown good stability in friction coefficient at a high speed and high energy braking conditions. Therefore, flame spraying technique for cermet coating materials has been chosen as a good method to produce coatings on a metallic substrate. In this study, a sample cast iron disk with ventilation channels coated with NiCrBSi-%35W2C powder by the flame spraying method were investigated. The braking performances of uncoated disk and coated disk were tested according to SAE J2430 test standard. It was found out that the coated disk had lower surface roughness and higher coefficient of friction than the uncoated disk. The NiCrBSi-%35W2C coated disk exhibited less wear, a higher coefficient of friction and longer life than the uncoated disk. As a result, the NiCrBSi-%35W2C coated disk could be a much better alternative for a new generation of brake disks in the motor vehicles than the uncoated disk.