Development of Wear Mechanism Maps for Acrylonitrile Butadiene Styrene Hybrid Composites Reinforced With Nano Zirconia and PTFE Under Dry Sliding Condition

Abstract

Acrylonitrile butadiene styrene (ABS) polymer is cost-effective and also possesses high toughness and resistance to corrosive chemicals. However, pure ABS does not show significant wear resistance and also it has a high friction coefficient. Incorporation of a solid lubricant and nanofiller in a polymer matrix improves its tribological properties significantly. The addition of solid lubricant makes it suitable for application where self-lubrication is desirable (sliding bearings, gears). This paper deals with the study of tribological behavior of ABS hybrid composites reinforced with nano zirconia and polytetrafluoroethylene (PTFE). ABS hybrid composites with varying proportions of nano zirconia and PTFE were prepared using melt blending. Dispersion of reinforcement in the polymer matrix has been studied with the help of transmission electron micrographs. Influence of reinforcements on the mechanical behavior is studied by tensile testing according to the ASTM standard. The tribological behavior of composites was determined in a pin-on-disk tribometer according to the ASTM G99 standard. Worn surfaces were analyzed using scanning electron microscope (SEM) in order to identify the different types of wear and various wear mechanisms. Transfer film formation was studied by analyzing the counterbody surface. A wear mechanism map has been developed, which helps in identifying various wear mechanisms involved under given loading conditions. The results reveal that the addition of PTFE reduces the wear rate and coefficient of friction (COF) significantly. Nano zirconia effectively transfers the load, thereby improving wear resistance, and the addition of PTFE results in continuous transfer film formation thereby reducing the COF. Also from the wear map, it has been identified that abrasion, adhesion, plowing, plastic deformation, melting, and delamination are the dominant wear mechanisms involved.