Effect of Loads, Speeds, Temperatures and Water Lubrication on Friction Behaviors and Wear Mechanisms of Carbon Fiber Reinforced Composites

ABSTRACT Carbon fiber reinforced epoxy resin composites (CFRP) exhibit exceptional wear resistance and fatigue performance, making them promising candidates for enhancing the durability of structural components. This study systematically investigated the friction behavior and wear mechanisms of CFRP under varying operational conditions, including applied loads, sliding speeds, service temperatures, and water lubrication. Among these factors, applied load emerged as the most influential parameter, significantly altering the interfacial shear stress due to tangential displacement, whereas water lubrication exhibited the least impact. Under a 2000 g load, the wear rate and scratch width increased by 159.3% and 123.5%, respectively, compared to those under a 500 g load. This deterioration was primarily attributed to irreversible de‐bonding damage at the fiber/resin interface, leading to pronounced delamination wear. Elevated temperatures further exacerbated wear, with the wear rate at 100°C and 120°C increasing by 76.7% and 110.3%, respectively, compared to room temperature. This phenomenon was linked to the transition of the epoxy resin from a glassy to an elastic state, promoting fatigue wear. In contrast, sliding speed and water lubrication exerted minimal influence on the friction coefficient, with variations of < 20%. Notably, under 60°C water lubrication, the coefficient of friction fluctuated by only 9.6%, owing to the dual role of water molecules in lubrication and heat dissipation, which mitigated severe wear, leaving only mild abrasive wear. However, at a sliding speed of 120 mm/s, the wear rate surged by 82.2% compared to that at 60 mm/s, a consequence of the mismatched deformation between the surface and subsurface of CFRP, which induced adhesive wear. These findings provide critical insights into the operational limits and failure mechanisms of CFRP, offering valuable guidance for optimizing its performance in practical applications.