Abstract
Polyoxymethylene (POM) has excellent self-lubricating properties and is widely used in tribological applications. However, the mechanism of wear debris formation during polymer–polymer friction remains unclear. In this study, acrylic resin was employed as a transparent counter material to enable in-situ optical observations of the sliding interface formed by the surfaces of a POM ball and an acrylic resin disc. Pin-on-disk tests were conducted at different sliding speeds, and the friction coefficient and near-interface temperature were measured. In-situ optical observations and SEM analyses were also performed to evaluate wear debris flow and material transfer. At a sliding speed of 0.25 m/s, wear progressed relatively gradually, debris flow was confined to grooves and accompanied by localized stagnation, transfer to the acrylic side remained localized, and the debris mainly exhibited a flake-like morphology. In contrast, at 0.56 m/s, wear progressed more rapidly, and debris was generated over the entire POM surface, flowed continuously across the interface without significant accumulation or re-adhesion, and predominantly exhibited a roll-shaped morphology. A thick transfer layer covering the wear track was also formed on the acrylic side. These findings suggest that the sliding speed strongly influences debris flow and transfer, thereby governing the mechanism of wear debris formation in POM–acrylic resin sliding systems.
