Multi-Objective Optimization of Machining Process Parameters in Wire-Cut Electric Discharge Machining of Inconel X750 Alloy by Combinatorial Approach

Difficult-to-cut materials, generally high hardness, strength and toughness, are generally difficult to machine in conventional machining. Also tool wear is high in conventional machining processes. Wire Cut Electric Discharge (WEDM) machining is particularly used for machining complex profiles, demanding very high accuracy. The current work focuses on the optimization of roughness of a surface that is machined using WEDM; the process parameters considered for optimization are pulse-on-time (Pon), pulse-off time (Poff), wire feedrate (WFR) and spark gap voltage (SGV). One of the surface integrity aspect is considered as surface roughness (SR) and other related to machining output considered as material removal rate (MRR) for the output responses. The paper presents, a multi-criteria decision making technique, with Grey Relational Analysis (GRA) integrated with Particle Swarm Optimization (PSO) for optimizing the process parameters. Further, confirmation tests that were conducted also validated the improvement in SR and MRR.