Investigation of Electro Discharge Machining of Aerospace Alloys

Abstract

Titanium and nickel-based alloys are materials of choice for many applications. Their high strength and low density make them a suitable candidate for aerospace applications. Besides these properties, these alloys exhibit remarkable corrosion resistance and biocompatibility. These properties make them suitable candidate for orthopedics implants. Whereas the reactivity and heat resistance of these alloys renders them difficult to machine. One of the known substitutes to the traditional cutting method is wire electrical discharge machining which is commonly being used nowadays to process materials that are tough to be machined on conventional machines being hard in nature, such as aerospace alloys. Based on previous research involving the effect of input variables on the output variables, this research aims to identify best machine setup for a quality product. Starting with Peak current, Wire feed rate, Pulse on time and Pulse off time as input parameters, and their effect on surface roughness and kerf width has been studied. Influence of these process conditions of the wire electro-discharge machining on grains distortion analyzed through SEM analysis results. Peak current and pulse on time are significant factors for kerf width of Inconel 600, for the kerf width of titanium alloy peak current and wire feed rate are found significant factors. For smoother surface, higher feed rate and intermediate current values are preferable for Inconel 600, however for titanium alloy high pulse off time and intermediate values of peak current are desirable for smooth surface finish. More grain distortion was observed for samples with greater surface roughness