Novel experimental approaches for the tribological characterization of vegetal lubricants

The environmental and toxicity issues of conventional lubricants as well as their rising cost related to a global shortage and their poor biodegradability led to renewed interest in the development of environmentally friendly lubricants. Environmental legislation by Occupational Safety and Health Administration (OSHA) and other international regulation authorities discourage the use of mineral oil-based lubricant and environmental-harmful additives. This gives increasing demand for green lubricants and lubricant additives in recent years. Products currently available from vegetal based oils include for example tractor transmission hydraulic fluid, industrial hydraulic fluids for process and machinery, metal working oils and coolants, but, in any case, it is necessary a deep rheological and tribological characterization of the vegetal base stocks used for formulate the specific lubricant. The aim of this perspective paper is to illustrate a novel experimental approach for the characterization both the tribological properties and the wear protection ability of investigated vegetal base stocks. With this in mind, even if no experimental results were reported in this paper, a novel and promising design of experiments approach was descripted based on reciprocating tribometer for the tribological oils characterization and on the pin on disk followed by the optical wear debris analysis for the wear protection ability assessment of the investigated base stokes.