On the role of capillary and viscous forces on wear and frictional performances of natural fiber composites under lubricated polishing

Abstract

This paper aims to investigate the frictional and wear performances of natural flax fibers reinforced polypropylene composites subjected to lubricated mechanical polishing. Particularly, the interactions between the biocomposite surfaces and two different liquids (oil and water) are considered using a rotary tribometer where the counter-face is fed by silicon carbide (SiC) abrasive papers. Friction and wear at dry, water and oil-lubricated polishing are hence studied. The biocomposite worn surfaces are examined using a scanning electron microscope (SEM) and an atomic force microscope (AFM). Results show a significant influence of the lubricant type on the wear and frictional performances of flax fiber composites. The lubricated friction behavior is dependent on both the hydrophilic and oleophilic properties of flax fibers. In addition to the abrasive wear, while the thermal softening of the biocomposite controls the adhesive wear mechanism at dry polishing, changing the lubricant type from water to oil leads to modify the adhesive wear sources from only capillary forces to capillary and viscous forces, which contributes to increasing the wear of flax fiber composites under oil-lubricated polishing.