Influence of cutting fluid conditions and cutting parameters on surface roughness and tool wear in turning process using Taguchi method

• Fluid flow mechanism of cutting fluid in machining process is explained.
• Effect of fluid condition and cutting parameters on surface roughness and tool-life.
• Optimization of cutting parameters to achieve good surface roughness and long tool life.
• Confirmation test with predicted cutting parameters.

In this experimental work, the effect of various cutting fluid levels and cutting parameters on surface roughness and tool wear was studied. Taguchi orthogonal array was employed to minimize the number of experiments. The experiments were carried out on mild steel bar using a TiCN + Al2O3 + TiN coated carbide tool insert in the CNC turning process. The effect of feed rate was found to be the dominant factor contributing 34.3% to surface roughness of the work-piece. The flow rate of the cutting fluid also showed a significant contribution (33.1%). However, cutting speed and depth of cut showed little contribution to surface roughness. On the other hand, cutting speed (43.1%) and depth of cut (35.8%) were the dominant factors influencing tool wear. However, application of cutting fluid (13.7%) showed a considerable contribution, while the feed rate gave the least contribution to tool wear. The optimum cutting conditions for desired surface roughness and tool wear were at a high level of cutting speed, medium level of depth of cut, low level of feed rate and low-flow high-velocity (LFHV) cutting fluid flow from the selected levels.