Characterization of vegetable oil as cutting fluid

Metal cutting fluids have been used in cutting operations for a long time. These types of fluids, called metalworking fluids (MWF), guarantee the essential requirements in terms of quality of the machined components and stability of the process in metal processing. The functions that the cutting fluids must fulfill are in essence the following: 1) refrigeration; 2) lubrication of the machine tool and reduction of the coefficient of friction between tool and chip; 3) prevention of tool & chip welding phenomena and built-up-edge formation. (effect of strong compression and great heating between both parts); 4) separation of the chip already torn from the piece; 5) protection against corrosion. Usually the majority of MWFs are based on non-renewable mineral oils. However, the growing attention to the environment by governments on industrial activities and the more severe conditions of cutting operations are leading to the study and development of new base stock vegetable oil fluids for cutting operations. For these reasons, the aim of this study is to investigate the properties and the performances of base-stock vegetable oil as an eco-friendly metalworking fluid in terms of: a) refrigeration of the cutting tool; b) lubrication between tool and chip in a milling process by measuring the power absorbed by the machine tool by using a digital clamp meter; c) surface finish of the manufactured specimens by using confocal microscopy. The tested and mechanized materials were Aluminum Alloy AA2030 and AISI 1050 Carbon Steel. During the investigation, three different cooling and lubrication strategies were examined during the milling process: Dry, Mineral oil emulsion and Jatropha oil emulsion.