Statistical and experimental evaluation of multi-performance in turning of AISI D6 using Grey relational analysis

In this study, the impact of machining variables and the relationship among the performance outputs (surface quality and tool life) and process variables were investigated using Grey relational analysis (GRA) in finish turning of AISI D6 tool steel with the CBN insert. The experiments were done under different cutting speeds, cutting depths and feed rates. Hardening heat treatment was applied to the workpiece used in experiments, and the hardness is 62 HRC after the heat treatment. The most important and best suitable process variables were found by the GRA and Taguchi experimental design method. According to the obtained results, the life of the cutting tool shortened with the increasing cutting depth, feed rate and cutting speed, and the increment in feed rate and cutting depth resulted in a deterioration of the surface quality of work material. The tool wears increased with a rise in all cutting parameters, while the surface quality only increased with raising the cutting speed. During the turning of AISI D6 steel, it was verified that CBN cutters were not the appropriate choice for high cutting speed and feed rate.