Optimization of Fillers in Resin-Based Friction Materials and Analysis of Wear Mechanism Through Orthogonal Design

The inherent toxicity of antimony-based fillers in conventional resin-based friction materials necessitates the exploration of sustainable substitutes for wind turbine braking applications. This study therefore aims to formulate a high-performance, environmentally benign alternative using a ternary filler system comprising fly ash microspheres (industrial solid waste), molybdenum disulfide (MoS₂), and talc. To optimize the filler proportions, an L9(3⁴) orthogonal array design was implemented, systematically assessing the influence of each component on the friction coefficient, wear rate, and mechanical integrity. Dry sliding wear tests were conducted against an HT250 cast iron disc to simulate operational conditions. The experimental results identify the optimal composition (T3: 6 wt% MoS₂, 6 wt% talc, 4 wt% fly ash) as achieving a low wear rate of 0.7 × 10^-7 cm³/(N·m) at 350 °C, alongside an 88% recovery rate for the friction coefficient, with these key tribological metrics proving directly comparable to those of traditional antimony-containing formulations. The underlying mechanism for this improved performance lies in the synergistic interaction of the three fillers, which facilitates the development of a stable and cohesive tribofilm on the contact surface. Furthermore, analysis confirms that abrasive wear remains the prevailing material removal mechanism, thereby validating the practical feasibility of this newly developed, non-toxic composite material.