Optimization of Tribological Process Parameters of Flax Fiber Reinforced Polymer Composites Using Box-Behnken Design and GRA-PSO

This study investigates the optimal tribological process parameters for a flax fiber-reinforced polymer composite (FRPC) to maximize the coefficient of friction (COF) while minimizing the specific wear rate (SWR). The tribological characteristics were evaluated using a pin-on-disc setup under three operational conditions: load (30, 40, and 50 N), speed (100, 250, and 400 rpm), and sliding distance (100, 250, and 400 m). The Box-Behnken Design (BBD) was employed, with optimization performed through Grey Relational Analysis (GRA) and Particle Swarm Optimization (PSO). Analysis of Variance (ANOVA) was used to interpret the results. The results demonstrated that the optimal conditions, as determined by PSO, were a load of 35.8 N, speed of 220.3 rpm, and sliding distance of 209.6 m. The ANOVA revealed that load significantly influenced both the COF and SWR, with higher loads leading to increases in both the COF and SWR. A single-objective PSO was conducted for both COF and SWR. GRA evaluated optimal weights for COF and SWR of approximately 51% and 49%, respectively. A confirmatory experiment was conducted at the obtained PSO parameters, and the error was calculated. Additionally, optical and scanning electron microscopy (SEM) were used to analyze the morphologies of the tested samples.