Influence of nano-potassium titanate particles on the performance of NAO brake-pads

Abstract

The present era is dominated by nano-materials. Researchers are keen to explore the potential of nano-particles (NPs) in composites because of their intensive interaction with the matrix and surfaces due to very large surface area.Potassium titanate (KT) is used as a filler in a good quality non-asbestos organic (NAO) friction materials (FMs). Based on a little information available in the literature, it is claimed to reduce friction-fluctuations, fade and wear. However, exact role of KT in FMs is not so clear due to contradictory findings. Interestingly, no paper is available on exploration of NPs of KT in FMs.Keeping this in view, two realistic multi-ingredient NAO FMs in the form of brake-pads with identical compositions but differing in size of a theme ingredient, KT were developed. One composite was without KT (K0), while two composites containing 3% micro and 3% nano-KT particles were designated as KM and KN. These were characterized for physical, mechanical and tribological performance. Initial tribo-evaluation of composites was done on a reduced scale prototype (RSP) under various operating conditions. Final tribo-performance was evaluated on a full scale brake dynamometer following JASO C 406 Schedule using gray cast iron disc. Various performance parameters such as performance µ, fade µ, recovery µ; fade ratio, recovery ratio, wear resistance etc. were used to evaluate the performance of FMs.Both testing data (prototype and realistic machine) showed that almost all performance parameters were significantly and beneficially affected due to NPs of KT. Nano-KT particles proved to improve performance µ and wear resistance significantly compared to its micro-partner. Worn surface analysis of pads and discs was done to understand wear mechanism by SEM and EDAX technique. It was finally concluded that Nano-KT particles have a potential to enhance performance of FMs significantly.