Multi-objective optimisation of electrical discharge machining process using Derringer's desirability function approach

摘要

Proper selection of manufacturing conditions is one of the most important aspects in the die sinking electrical discharge machining (EDM), as these conditions determine important characteristics such as surface roughness, material removal rate and tool wear rate. In the present work, mathematical models have been developed for relating the surface roughness and material removal rate to machining parameters like pulse-on time, pulse-off time and discharge current. Response surface methodology (RSM) has been applied for developing the models using the technique of design of experiments and multi-linear regression analysis. Validation experiments were conducted to demonstrate the effectiveness of these models. A desirability function approach popularised by Derringer and Suich was used to optimise the EDM process with multiple objectives. Optimal parameter combinations have been identified for machining in finish and roughing region. The study demonstrates that the EDM process parameters can be adjusted to achieve higher material removal rate and better surface roughness simultaneously.