Effect of powder mixed dielectric on Surface properties in Electric Discharge Machining

Abstract

In the process technology, as there are numerous advances at rapid rate, a large number of new materials are being developed every day. These materials have the combination of properties, like light weight, corrosive resistance, high strength etc., which is not easy to obtain in general. The important aspect is that they satisfy the demands of today’s industry, but the major problem is that it is very difficult to machine the newly developed materials. So, in order to manipulate them, newer machining methods have been developed. These methods are more efficient than the conventional ones. Electric discharge machining (EDM) is one of the most widely used methods among the new techniques. The main reason behind the popularity of the EDM is that its capability of machining the hard to machine materials and intricate shapes. EDM has been employed to effect/change the surface properties such as roughness and hardness of the die steels by varying the electrode material and by adding the various powders in the dielectric. In this thesis work the literature available in the area of Surface modification by PMEDM (Powder Mixed EDM), EDM in general and effect of PMEDM on Tool Wear Rate and Material Removal Rate has been reviewed. Experiments were designed using Taguchi method so that effect of all the parameters could be studied with minimum possible number of experiments. Using Taguchi method, Appropriate Orthogonal Array has been chosen and experiments have been performed as per the set of experiments designed in the orthogonal array. Signal to Noise ratios are also calculated to analyze the effect of PMEDM more accurately. From the point of view of industrial applications, die steel is a very important material and that’s why for the purpose of experimentation EN31 die steel with copper electrode and kerosene as dielectric has been used.