Optimization of tribo-performance of brake friction materials: Effect of nano filler

This research work examined brake friction materials containing nanoclay and multi-wall carbon nanotube (MWCNT) to determine their effect on the tribo-performance. The tribo-performance of brake friction materials were investigated using a Kraus friction testing machine conforming to the Regulation-90 as per the ECE (Economic Commission for Europe) norms. The result of experiment indicated that MWCNT enhances the friction and fade performance, but depresses the wear performance, whereas nanoclay improves the wear and recovery performance but simultaneously depresses the friction performance as well. Variability coefficient improves with nanoclay contents whereas, friction fluctuations (μmax–μmin) improve with MWCNT content. Preference selection index (PSI) method was applied to rank the friction materials by using several performance defining criterions (PDC) including coefficient of friction (μ), wear, friction recovery-%, friction fade-%, stability coefficient, variability coefficient, friction fluctuation and disc temperature rise, respectively. These results show that the best combination of tribological properties was exhibited by nanoclay filled formulation. •Brake friction materials based on nanoclay and MWCNT were developed.•Nanoclay was more effective in improving recovery and wear performance.•MWCNT was more effective in improving friction and fade performance.•Preference selection index method was used to find the optimal formulation.