Effect of deep cryogenic treatment on performance measures in wire electrical discharge machining process during taper cutting operation

摘要

Deep-cryogenic treatment brings some remarkable improvements in mechanical properties by refining the microstructure of the materials. In recent times, cryo-processing has been successfully applied to toughened and high strength to weight ratio work piece materials and tools in electrical discharge machining (EDM) and wire electrical discharge machining (WEDM) for improving machining efficiency. In the present investigation, coated Bronco cut-W wire electrode and Inconel 718 work piece are subjected to deep cryogenic treatment (-196°C). The microstructure of deep cryo-treated and untreated wire electrode and work piece is observed by scanning electron microscope (SEM). The effect of deep cryogenically treated wire electrode and work piece on various performance characteristics are studied during taper cutting operation in WEDM process. Taguchi's experimental design has been applied to determine the optimal parameter setting considering six input parameters such as part thickness, taper angle, pulse duration, discharge current, wire speed and wire tension on various performance measures such as angular error, surface roughness and cutting speed. The study reveals that deep cryogenic treatment of both wire electrode and work piece can improve the machining performance in WEDM.