Abstract
This study examined the impact of cutting parameters and fluids on machining performance metrics, such as machine vibration rate and sound level, when turning AISI 1525 steel using tungsten carbide tools. Jatropha oil was used in two forms, minimum quantity lubrication and emulsion. Jatropha MQL was applied directly to the cutting region without any additives or water. Jatropha emulsion was formulated based on 4
4
full factorial techniques. Jatropha emulsion was formulated by mixing water, biocide, anticorrosive agent, antifoam agent, and emulsifier. The pH of the emulsified sample was used to determine the best formulation through optimization. Jatropha emulsion and Jatropha MQL were compared with their mineral oil equivalent during machining under Taguchi L
9
orthogonal array settings. The hardness of the workpiece was determined at every 5 mm diameter. Additionally, the microstructure of the workpiece was examined at 5 mm, 35 mm, and 70 mm diameters of the shaft. Multi-response optimization was performed using TOPSIS to determine optimal cutting parameters to minimize machine vibration rate and machine sound level. Results showed that jatropha MQL and jatropha emulsion reduced machine vibration rate drastically as compared to mineral oil counterparts. Jatropha MQL surpassed jatropha emulsion, mineral emulsion, and mineral MQL by 75.8%, 81.2%, and 90.5%, respectively. In terms of sound intensity, Jatropha oil MQL performed significantly better than other cooling and lubricating fluids based on general process parameter results. The hardness of the material increases as the diameter increases and it varies between 70.2 HBR and 150.4 HBR. Microstructural analysis showed the presence of pearlites and ferrites on the selected shaft diameters. Findings showed that the lowest machine vibration and machine sound values were achieved with experimental trial 1 such as spindle speed (355 rev/min), feed rate (0.10 mm/rev), and depth of cut (0.75 mm) in all cases of machining fluid. The optimal solutions of spindle speed, feed rate, and depth of cut were 355 rev/min, 0.10 mm/rev, and 0.75 mm; 355 rev/min, 0.15 mm/rev, and 1.00 mm for machine sound and machine vibrations, respectively.