Machining Performance and Parametric Modelling for AISI 304 Steel using Biodegradable Cutting Fluid

The non-biodegradability, non-recyclability and toxicity of conventional cutting fluids such as mineral oils, have raised serious concerns within the research community and prompted the renewal of research in this area with focus on replacing them with eco-friendly cutting fluids. Although several vegetable oils have been explored, there are limited work on castor oil-palm kernel oil blends that integrates physiochemical characterization, machining performance and parametric modelling for AISI 304 steel. This study evaluates the potential of using castor oil-palm kernel oil blend as green substitute for mineral oil (Aquicut 40) in metal cutting with application to turning of AISI 304 steel. Samples of castor oil, palm kernel oil, Aquicut 40 oil and formulated palm kernel-based oil were characterized by investigating the physiochemical and lubricity properties. Also, models were proposed and applied to the experimental data for validation of the results. The optimal process parameters were evaluated using Taguchi’s signal-to-noise ratio. The developed oil was found to be basic (pH value: 10.10), corrosion resistant, stable, with dark yellowish coloration and generally liquid at room temperature. The application of the green oil at higher spindle speed, feed rate, and depth of cut, resulted in maximum cutting temperature (78.0℃). The optimal process parameters were achieved at lower cutting velocity and lower feed rate. The proposed models for predicting the machining parameters were suitable and reliable, with prediction accuracy above 90%. The cutting fluid promises to be environmentally friendly and safe in machining operations.