AN INVESTIGATION OF TOOL WEAR RATE, MATERIAL REMOVAL RATE AND SURFACE ROUGHNESS BY COPPER ALLOY TOOL ON STAINLESS STEEL IN EDM PROCESS

Abstract

in the present dissertation work the influence of machining parameters such as discharge current (I), pulse on time (T0) and pulse off time (Tn) on the electric discharge machining of AISI stainless steel 202 using two types of copper alloys as tool materials has been done. Comparison between both the tool materials has been done. Electrode wear rate, material removal rate and surface roughness were the main responses investigated in this work. For design of experiments, mathematical modeling and finding out the interactive effect of process parameters on machining performance outputs, response surface methodology approach (RSM) has been applied. On the basis of this approach, regression equations for the responses were also generated. Optimality search of the process parameters has been performed in order to get optimum value of responses for efficient machining operation. For finding the significance of generated mathematical models analysis of variance (ANOVA) technique has been used. This study also focuses on the surface modifications by electric discharge machining (EI)M). Various testing and analysis techniques such as atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction were used for this purpose. Discharge current was found as very important parameter. Rest electrode wear rate and material removal rate was obtained by using Cu-Cr-Zr tool having valuesO.000 155 mg/mill and 0.048 125 mg/mm, respectively. Cu-Te tool gives best surface roughness with value 1.59 urn. It was observed that for efficient machining optimization of process parameters is very important.