Challenges in Formulating Vegetable Based Metalworking Lubricants: A Review

Abstract

The hazardous mineral based lubricating oils are being banned worldwide due to their potential negative environmental impact. The mineral based oil does not meet the requirements of metalworking process without the support of anti-wear, extreme-pressure or extreme temperature additives. Because of additives, they become expensive to cater the needs of special requirements in industries. Besides, being environment friendly, vegetable based lubricants have exclusive properties such as high lubricity, polar nature, high viscosity index and flash point and low evaporation rate. Still they have not yet fully replaced mineral based lubricants due to issues related to their oxidation stability and inappropriate chemical structure. The challenges are to improve certain characteristics of vegetable based lubricants along-with excellent tribological properties. Advanced additive technology and chemical modifications of vegetable oils make them fit for the metalworking applications. In this review article, based on the available literature and recently published data, developments related to vegetable based lubricants and its suitability for metalworking operations are reviewed. Also, challenges in formulating vegetable based oils are put-forth.