Application of grey relational analysis in high-speed machining of hardened AISI D6 steel

Abstract

This study reports an optimization of finish turning of hardened AISI D6 (60 HRC) cold work tool steel with ceramic and cubic boron nitride cutting tools using grey relational analysis. Optimization of the process parameters was performed using quality characteristics, i.e. tool wear, surface roughness, machining force and specific cutting force. Analysis of variance was used for observing the most influencing machining parameters on the quality characteristics. Evaluation of tool wear type and wear mechanism was done by tool makers’ microscope and scanning electron microscope analysis. The optimal process parameters were calculated using grey relation grade and confirmation test was performed. Based on analysis of variance results, the feed rate is the most significant controllable machining factor for the finish hard turning of AISI D6 according to the quality characteristics. Flank and crater wears were the prominent wear types on the ceramic and cubic boron nitride inserts. Grey relational analysis was successfully applied on optimization of high-speed finish hard turning of hardened AISI D6 using multi-performance characteristics.