WED-machining performance by reciprocating molybdenum wire on Inconel 718 with water or hydrocarbon dielectrics

Abstract

The Inconel 718 superalloy is widely used in petrochemical, energy, aerospace, nuclear power plants, and many other applications where components are subjected to high temperatures and corrosion environments. This alloy is most used due to its combination of good mechanical properties and relatively low cost compared to other supperalloys. Nevertheless, its mechanical properties and workpieces with very complex geometries are difficult to be manufactured by conventional machining properties. It is observed that notch wear at the cutting tool tip and superabrasive carbides in Inconel 718 promote high abrasive cutting tool wear; high diffusion wear happens at cutting tool, continuous and tough chips cause degradation of the cutting tool, and both high temperature and thermal gradients occur at the cutting tools due to low thermal diffusivity of these alloys. Wire electrical discharge machining is a precision non-traditional machining process that appears as an alternative to the conventional machining process for any hard and electrically conductive material. The objective of this research work is to compare the technological performance of WED-Machining Inconel 718 using a reciprocating molybdenum wire electrode using two types of dielectric fluids (deionized water and 8% emulsion hydrocarbon) under different electrical parameters. Therefore, it presents the investigation of the discharge energy influences for five different levels of discharge durations and varying the wire run-off speed. Technological aspects labeled material cutting rate, kerf width, wire feed rate, and surface integrity were evaluated. The results revealed that the hydrocarbon presented a higher cutting rate than deionized water independent of the discharge energy applied. The hydrocarbon dielectric presented the best results for the wire feed rate compared to water fluid. The largest kerf width was attained for the deionized water, and the surface roughness increase is more pronounced for deionized water than hydrocarbon dielectric.