Parametric Study on Electrical Discharge Drilling of Aerospace Nickel Alloy

Abstract

Drilling of holes in difficult-to-cut aerospace materials with desired surface finish and accurate geometry is beyond the capability of conventional twist drills. Nonconventional machining methods which have the capabilities to offset the cutting difficulties of twist drills are currently being used for making holes in hard materials under the terminology of advanced machining processes (AMPs). Electrical discharge machining (EDM) is one such AMP which has been used in the present experiment for making holes in high nickel alloy with slight modification in sinking EDM machine. The concept of tool rotation is incorporated in sinking EDM machine and authors have termed it as electrical discharge drilling (EDD). The main objective of this experimental study is to study and analyze the impact of introduced tool rotation in EDD. Present experiment confirms that tool rotation has substantive effect on surface roughness (R _a ) and average circularity (C _a ) of the hole made by EDD process. Micrograph results of two samples of machined workpiece also substantiates with output results of introductory concept of tool rotation in EDM machine.

Keywords:

• Average circularity
• Average surface roughness
• Electrical discharge drilling
• Advanced machining processes

Notes

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