In braking systems, which consist of dry sliding lining against a pearlitic cast-iron disc, disc wear has a significant impact on the overall wear rate. In this work, dynamometer tests were conducted to find out the friction and wear behaviour of 20NiCrBSi-WC12Co cermet coating accumulated on the cast-iron disc by High velocity oxy-fuel spraying (HVOF) and the findings were compared with those of the uncoated disc. Braking tests of the coated and uncoated discs were performed on a full-scale brake dynamometer, which was designed in line with the SAE-J2430 Brake Effectiveness Procedure. Microhardness values, surface properties, scanning electron microscopy (SEM) analysis, energy dispersive x-ray (EDX) and x-ray diffraction (XRD) analysis of the discs were evaluated. As a result of these analyses, it was found out that cermet coating had a much higher microhardness and abrasion resistance with the combination of hard WC phase and mild Ni matrix compared to the conventional disc. The coated disc exhibited stable braking effectiveness with lower surface contact temperature. At the same time, this coating results in longer service life by reducing abrasive wear on the brake disc surface and a lower lining wear rate, reducing particle matter emissions to the environment.

Various international initiatives on environmental issues and the need to protect the environment are promoting the use of industrial waste in a variety of applications, including automotive brake pads. These studies show that the reuse of industrial waste can help to reduce the environmental impact. The development of environmentally friendly and cost-effective composites for use in a variety of engineering applications is the need of the century. The use of industrial waste in composite production is a possible solution for both problems. In this study, the potential use of talc, quartz and ceramic waste FFC fracture as a friction modifier in brake friction materials and its performance properties in accordance with industry requirements were investigated. The tribological, physical and mechanical properties of the brake pads were measured, and the friction surface morphology was investigated by scanning electron microscopy. According to the results obtained, the highest specific wear rate was observed in the FM3 sample. The FM2 sample with the highest hardness and average friction coefficient showed the lowest wear. FM4, FM5 and FM6 samples with high talc and quartz content exhibited low coefficient of friction characteristics compared to other samples.

This paper presents the findings of comparative research conducted to find out the braking performance of a Mo/NiCrBSi coated automobile brake disc. The friction and wear behavior of the Mo/NiCrBSi coating (CD) used for the disc material was evaluated using a laboratory scale disc-pad dynamometer and compared with a reference disc (RD). The coating was deposited by means of the atmospheric plasma spray process on a grey cast iron substrate. Braking tests were performed according to the SAE-J2430 test standard. Disc microstructures were characterized by SEM and XRD. It was found that the bonding strength was good with an infinite rating between the accumulated coating layer and the substrate. The results show that the coated brake disc has a comparable coefficient of friction and that the amount of wear is lower than that of the reference disc. The addition of ductile phases to the disc coating was beneficial in reducing the coefficient of friction to an acceptable degree and also effectively improving wear resistance.