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Despite the fact that Inconel 617 has prominent industrial applications, the machining characteristics of the same alloy are relatively unknown. The present study, therefore, aims at comparative evaluation of performance of WC, SiAlON and SiCw + Al2O3tools under different cutting parameters during dry machining of Inconel 617. Solid solution strengthening due to Ni-Cr-Mo-Co phases and precipitation strengthening due to M23C6carbide present in Inconel 617 specifically lead to rapid rate of tool wear. Finite element (FE) simulation is carried out to predict cutting zone temperature and tool wear followed by experimental validation. The results indicate that WC tool performs well in terms of cutting force, temperature and surface roughness under the condition of low cutting speed of 50 m/min due to low tool wear. The effectiveness of WC tool rapidly deteriorates under high cutting speeds of 150 and 250 m/min. Ceramic tools outperform WC under the condition of higher cutting speeds in terms of greater resistance to crater and flank wear, cutting force, temperature and surface roughness. However, depth-of-cut notch and nose chipping are the predominant modes of tool wear for ceramic tools during machining of Inconel 617.

In recent times, nickel-based super alloys are widely utilized in aviation, processing, and marine industries owing to their supreme ability to retain the mechanical properties at elevated temperature in combination with remarkable resistance to corrosion. Some of the properties of these alloys such as low thermal conductivity, strain hardening tendency, chemical affinity, and presence of hard and abrasives phases in the microstructure render these materials very difficult-to-cut using conventional machining processes. In this work, an experimental setup was developed and integrated with the existing electrical discharge machining system for carrying out powder-mixed electrical discharge machining process for Inconel 625. The experiments were planned and conducted by varying five different variables, that is, powder concentration, peak current, pulse-on time, duty cycle, and gap voltage based on the central composite design of response surface methodology. Effects of these parameters along with powder concentration were investigated on various surface integrity aspects including surface morphology, surface roughness, surface microhardness, change in the composition of the machined surface, and residual stress. Results clearly indicated that addition of powder to dielectric has significantly improved surface integrity compared to pure dielectric. Among the powders used, silicon has resulted in highest microhardness, that is, almost 14% more than graphite. Lowest surface roughness (approximately 50% less than pure kerosene) and least residual stress were obtained using silicon powder (approximately 8% less than graphite-mixed dielectric). Relative content of nickel was reduced at the expense of Nb and Mo after addition of powders like aluminum and graphite in dielectric during electrical discharge machining.