The Application of the Preference Selection Index Method to Find the Best Work-Tool Combination During Machining

The medium carbon steel (MCS), Inconel 718, and D2 cold work steel were machined with different carbide tool materials. Speed, feed, and depth of cut were the machining parameters. The machining chips were collected for SEM (scanning electron microscopy) examination of chip surfaces. Tensile tests were done for all samples. Accordingly, strain-hardening exponent “n” and strength coefficient “K” were determined using the true stress-true strain graphs on the log–log graph papers. The chip reduction coefficient (CRC, \( \zeta\) ) and von Mises stress (VMS) were determined for different experimental conditions. The three different work-tool combinations were the alternatives, and CRC and VMS were the criteria. The preference selection index (PSI) method was applied to find out the best alternative. The fracture toughness of Inconel 718 was found to be higher among the test samples. The strain-hardening exponent of Inconel 718 was lower. The Inconel 718 and brazed carbide tool combination was ranked best, followed by D2 cold work steel and medium carbon steel. The result was validated by chip macrographs and SEM observation of chip surfaces.