Optimizing abrasive wear in sustainable MCC reinforced hemp bamboo epoxy composites for tribological applications

This study investigates the two-body abrasive wear characteristics of hybrid hemp and bamboo fibers in woven form epoxy (H/B F-Ep) composites reinforced with micro-crystalline cellulose (MCC) using a response surface methodology (RSM) framework and microstructural analysis. The effects of MCC content, emery paper grit, load, and abrading distance, on weight loss, coefficient of friction (CoF), and surface roughness (Ra) were assessed using four factors and three levels using Box–Behnken design. Analysis of variance (ANOVA) was used to develop and statistically validate quadratic regression models, which demonstrated strong predictive ability, a non-significant lack-of-fit, and high coefficients of determination (R² = 95.84–97.06%). Emery paper grit and abrading distance dominate wear loss, MCC content controls frictional response, and both MCC and grit have a substantial impact on surface roughness, according to an ANOVA. Strong nonlinear wear behavior under severe abrasion is indicated by significant interaction and quadratic terms, especially grit2 and filler–grit coupling. Optimized MCC loading reduces micro-cutting and stabilizes tribo-layer development, as indicated by main-effects and interaction plots. The statistical results were supported by SEM measurements, which showed a shift from severe micro-ploughing and fiber pull-out in unfilled composites to moderate abrasion and compacted tribo-films at the optimal MCC content. To minimize wear loss (0.0385 g), CoF (0.27), and Ra (1.62 μm), with an overall desirability of 0.96, multi-response desirability optimization determined that 3 wt% MCC, 400-grit abrasive, 150 m abrading distance, and 10 N load were the optimal settings. A strong framework for customizing natural fiber hybrid composites for tribological applications is provided by the combined RSM–SEM technique.