Performance Evaluation of Chemically Modified Crude Jatropha Oil as a Bio-based Metalworking Fluids for Machining Process

Metalworking fluids (MWFs) acts as cooling and lubrication agent at the cutting zone in the machining process. However, conventional MWFs such as mineral oil gives negative impact on humans and environment. Therefore, the manufacturer tends to substitute mineral oil to bio-based oil such as vegetables and synthetic oil. There is a need to develop environment friendly MWFs as an alternative to the use of lubricant. The aim of this research is to evaluate the performance of chemically modified jatropha oil-based trimethylolpropane (TMP) ester from crude jatropha oil (CJO) as bio-based MWFs. Modified jatropha oil (MJO) was developed by transesterification process with different molar ratios of jatropha methyl ester (JME) to TMP. Afterwards, MJOs were tested on viscosity, density and tribology according to American Society Testing and Materials (ASTM) conditions. Then, the samples were compared with synthetic ester (SE) and CJO on the orthogonal cutting condition. Those lubricants were supplied using minimum quantity lubrication (MQL) technique. The result shows that the viscosity of oils affects the coefficient of friction (COF) and wear scar diameter (WSD). The machining performance of MJO was comparable with SE in terms of cutting force and maximum cutting temperature. It shows that MJO was significantly improved the lubricating effect thus becomes a suitable candidate to substitute SE as a machining lubricant.