“Cenosphere–Molybdenum Disulfide”–New Filler–Lubricant Combination for Performance Synergism in Composite Friction Materials

Short-fiber (e.g., steel wool, rock fibers, and kevlar) reinforced flyash cenosphere–molybdenum disulfide combination-filled phenolic composite materials for friction braking applications were developed and evaluated for their physical (density, void fraction, acetone extraction, and ash content), mechanical (hardness, compressibility, shear strength), and thermal characteristics (thermogravimetric analysis (thermo gravimetric analysis (TGA)/differential thermo gravimetry). Performance correlations between thermomechanical characteristics and friction braking data obtained from Krauss friction testing machine is attempted. The frictional fade (μ_F) and recovery (μ_R) behavior vis-a-vis amplitude of friction fluctuations (μ_max–μ_min) performance were observed to be enhanced due to the incorporation of “cenosphere–molybdenum disulfide” combination. The enhanced wear resistance was attributed to the lower temperature sensitivity of posttemperature degradation kinetics. Analysis of friction and wear data indicated μ_F and intrinsic material coefficients to be major determinants for μ_P and wear, respectively. Our study demonstrates the performance synergism due to the incorporation of cenosphere–molybdenum disulfide as the hybrid “filler–lubricant” combination in composite materials for friction braking application.