Study of tribological properties of vegetable oil added with graphite as additives for lubricants

Abstract

Conventional liquid lubricants are constituted of a base oils and (nano)additives presenting specific properties, such as friction reduction and antiwear performances. Mineral or synthetic base oils are used due to their stability and especially their competitive prices. Vegetable oils (VO) owing the increasing interest of the environmental impact constitute a suitable alternative for lubrication. Two different VO are studied. In a first part, the comparative effect of the addition of VO as additive on the tribological performances of dodecane, the oil-based is investigated. Previous studies have shown that the friction properties of graphite particles in the presence of dodecane drecrease. We evaluate the influence of VO as additive on the properties of graphite/VO1/dodecane and graphite/VO2/dodecane lubricant mixtures. Raman spectroscopy and scanning electron microscopy performed to analyze the tribofilms after friction confirmed the collective liquid/particles effects inside the contact during sliding.