Performance Improvement of Eco-Friendly Near-Dry Wire-Cut Electrical Discharge Machining Process Using Coconut Oil-Mist Dielectric Fluid

Abstract

In this research, the minimum amount of bio-degradable coconut oil mixed with pressurized air (oil-mist) was first used as dielectric fluid in near-dry WEDM to promote eco-friendly cutting processes. The kerf width (KW), cutting speed (CS), and wire wear ratio (WWR) of coconut oil-mist and demineralized water-mist near-dry WEDM of Monel-K500 alloy have been compared by Taguchi L27 orthogonal array. Experiments were conducted using operating parameters such as air pressure, the flow rate of mixing coconut oil, spark current, pulse duration, and pulse interval. The surface topography of the KW and wire tool surfaces of both near-dry processes are also compared using the scanning electron microscope (SEM) tests. The KW and WWR of the coconut oil-mist process are 6.82% and 15.49% lower, and CS is 21.71% higher than the water-mist process. The contribution of each parameter to responses was also comparatively analyzed. The overall cutting characteristics of coconut oil-mist near-dry WEDM are better than the water-mist process.