Effect of coating on tool inserts and cutting fluid flow rate on the machining performance of AISI 1015 steel

The effect of cutting parameters, such as depth of cut, feed rate, spindle speed, cutting fluid flow rate and the number of layers deposited on the surface roughness and flank wear of a cathodic arc evaporation coated TiAlN/WC-C tungsten carbide cutting tool insert was investigated during CNC turning of AISI 1015 mild steel. The analysis of variance was applied to determine the critical effect of the cutting parameters. Taguchi orthogonal test design was used to optimize the process parameters. The depth of cut and deposition of layers altered the surface roughness (49 and 32 %, respectively) of the inserts. However, cutting speed, feed rate and the flow rate of the cutting fluid contributed only minimally to the surface roughness. In contrast, the number of layers deposited (48.66 %) and cutting speed (30.93 %) were the dominant factors affecting tool wear. The optimum cutting conditions for achieving the desired surface roughness consist of a medium level of cutting speed, a low depth of cut level, a low feed rate, high flow rate of cutting fluid and multilayer deposition. Minimal tool wear was achieved for the process parameters such as low cutting speed, low depth of cut, medium feed rate, medium flow rate of cutting fluid, and a multilayer deposited tool.