Multiple-Criteria Decision Analysis (MCDA) and Optimization of Hard Turning using Grey Relational Analysis (GRA)

This paper presents Multiple-Criteria Decision Analysis (MCDA) and Optimization approach for hard turning process of OHNS steel based with focus on wiper insert geometry. Wiper inserts are generally used in milling and turning operations for better surface finish. Since wiper insert can provide better surface finish during hard turning operation it can be considered as a potential substitute for grinding operation. In this investigation hard turning trials are conducted on OHNS steel with 55 HRc using conventional and wiper insert of 0.8 and 1.2 mm nose radius. Taguchi based L36 array with five process parameters namely type of insert, nose radius, speed (RPM), depth of cut and feed is used for Design of Experiment. Five responses are evaluated which are roughness parameters Ra and Rt, metal removal rate, power consumption and cycle time. Grey Relational Analysis (GRA) based Multiple-Criteria Decision Analysis (MCDA) and Optimization is carried out to find out optimum process parameters for responses mentioned above. The optimized process parameters during the investigation are Wiper Insert geometry with nose radius 1.2 mm, speed of 1200 RPM, feed of 0.2 mm/rev. and depth of cut 0.1 mm.