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“OPTIMIZATION OF PROCESS PARAMETERS IN ELECTRIC DISCHARGE
MACHINING PROCESS”
M. MUSTAFAIZ AHMAD, R. DAVIS, N. MAURYA, P. SINGH & S. GUPTA
Department of Mechanical Engineering, S.S.E.T., S. H. I. A. T. S, Allahabad, India
ABSTRACT
Electro Discharge Machining (EDM) is an extremely prominent machining process among newly developed
non-traditional machining techniques for “difficult to machine” conducting materials such as heat treated tool steels,
composites, super alloys, ceramics, hastelloys, nitralloy, nemonic alloys, carbides, heat resistant steels etc. In EDM, the
material removal of the electrode is achieved through high frequency sparks between the tool and the work-piece immersed
into the dielectric. The Material Removal Rate (MRR) is the important performance attributes of EDM process. The
machining parameters that achieve the highest MRR strongly depend on the size of the machining surface i.e. the engaged
electrode and work-piece surface. With upcoming worldwide applications of Titanium grade-2, machining has become an
important issue which needs to be investigated in detail.
A well-designed experimental were conducted with L18 Orthogonal Array (OA) based on the design of
experiment (DOE) with input factors like Peak Current (Ip), Pulse Time On (Ton), Duty Cycle (TAU) and Voltage Gap (V)
was considered for investigation. The effect of the machining parameters on the responses such as MRR was investigated.
In this research work, Regression analysis was used to find out the optimal levels of the parameters.
KEYWORDS: Electric Discharge Machining (EDM), Titanium Grade-2, Design of Experiment (DOE), Regression
Analysis, Material Removal Rate
1. INTRODUCTION
Electric Discharge Machining (EDM) is an electro-thermal non-traditional machining Process, where electrical
energy is used to generate electrical spark and material removal mainly occurs due to thermal energy of the spark.
EDM is mainly used to machine difficult-to machine materials and high strength temperature resistant alloys.
EDM can be used to machine difficult geometries in small batches or even on job-shop
Basis. Work material to be machined by EDM has to be electrically conductive. This technique has been
developed in the late 1940s where the process is based on removing material from a part by means of a series of repeated
electrical discharges between tool called the electrode and the work piece in the presence of a dielectric fluid. The electrode
is moved toward the work piece until the gap is small enough so that the impressed voltage is great enough to ionize the
dielectric. Short duration discharges are generated in a liquid dielectric gap, which separates tool and work piece. The
material is removed with the erosive effect of the electrical discharges from tool and work piece. EDM does not make
direct contact between the electrode and the work piece where it can eliminate mechanical stresses chatter and vibration
problems during machining. Materials of any hardness can be cut as long as the material can conduct electricity. EDM
International Journal of Mechanical
Engineering (IJME)
ISSN(P): 2319-2240; ISSN(E): 2319-2259
Vol. 5, Issue 4, Jun - Jul 2016; 45-52
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