Development and Optimization of Hybrid Friction Materials Consisting of Nanoclay and Carbon Nanotubes by using Analytical Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) under Fuzzy Atmosphere

Abstract

The tribo-performance of nanoclay and multi-walled carbon nanotube (MWNT) filled and graphite lubricated phenolic composites, reinforced with a combination of lapinus and kevlar fibers, have been evaluated on a Kraus friction testing machine. The combined fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order preference by similarity to ideal solution (FTOPSIS) approach, taking into account performance defining attributes (PDAs) such as friction performance, wear, friction-fade, friction-recovery, stability coefficient, variability coefficient, friction fluctuations and temperature rise of the disc, was used for the performance assessment of fabricated friction composite materials. The weight of different PDAs were evaluated by FAHP; μ-performance (0.144, 0.255, 0.435), wear (0.144, 0.255, 0.435), fade-% (0.073, 0.15, 0.307), recovery-% (0.063, 0.126, 0.268), stability coefficient (0.037, 0.075, 0.156), variability coefficient (0.032, 0.063, 0.136), frictional fluctuations (0.023, 0.037, 0.069), and DTR (0.023, 0.037, 0.069) respectively. FTOPSIS was employed to determine the optimal ranking of the friction composite materials as NC-7>NC-8>NC-6>NC-5>NC-3>NC-4>NC-2>NC-1. The alternative with kevlar: lapinus, 2.5:27.5 wt-% and graphite: nanoclay: carbon nanotube, 2.25:2.75 wt-% exhibits the optimal properties.