The Role of Lubricating Fluid Composition in the Tribological Response of Steel-Polymer Contacts

Rodríguez J.C.; Vidal Y.S. · Tribology in Industry (2026) · DOI: 10.24874/ti.2053.10.25.03

Resumen

This study investigates the influence of lubricating fluid composition and applied normal load on the tribological response of steel–polymer contacts. Experiments were performed using a ring-on-plate configuration with stainless steel rings and polymer plates (Nylon (Polyamide 6), polyoxymethylene (POM), and acrylic resin (UV-curable thermoset resin)) under controlled loads of 3–9 N and sliding speeds between 1 and 1000 mm/s. Three lubricants with similar viscosities but distinct chemical characteristics—Primol 352 mineral oil (highly refined paraffinic hydrocarbon oil), glycerol solution, and aqueous sucrose syrup solution (83wt%)—were tested to isolate the effect of fluid polarity and molecular composition. Results show that lubricant chemistry exerts a stronger influence on friction than viscosity, with polar fluids such as glycerol forming stable boundary films that significantly reduce the coefficient of friction, particularly on polymers with higher surface affinity toward polar fluids. The effect of normal load was material-dependent: nylon exhibited reduced friction at moderate loads, POM showed load-insensitive behavior, and resin displayed an initial decrease followed by stabilization. Surface observations confirmed that frictional trends correlate with film stability and interfacial adhesion. The findings highlight the critical interplay between lubricant polarity, surface chemistry, and contact pressure, providing valuable insights for the design of tailored lubricants for mixed-material mechanical systems.

Instituciones: Universidad Nacional de San Agustín de Arequipa