OPTIMIZATION OF PROCESS PARAMETERS IN EDM USING TAGUCHI METHOD WITH GREY RELATIONAL ANALYSIS AND TOPSIS FOR CERAMIC COMPOSITES

Silicon Nitride-Titanium Nitride ceramic composites are newly advanced material having the properties of high hardness, strength, toughness and low density. These kinds of materials are challenging to machine by conventional machining process because it causes severe tool wear due to its properties. Since the materials can be machined by non-conventional machining process like laser cutting and water jet, but these processes are limited. Electric discharge machining shows higher capability for cutting complex shapes with high accuracy. The present work focuses to optimize the process parameter for maximum material removal rate and minimum electrode wear rate. The experimental studies were conducted under varying pulse on time, pulse off time, dielectric pressure and discharge current. Taguchi L-9 orthogonal array was used to design the experiments. Grey relational analysis and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to optimize the process parameter and the results were validated by the confirmation tests. Thus the machining parameter for electric discharge machine was optimized to achieve higher material removal rate and lower rate on electrode. The result shows that the proposed technique is being effective to optimize the machining parameter for electric discharge machining process.