Optimization of electrical discharge machining parameters on hardened die steel using Firefly Algorithm

Abstract

Electric discharge machining (EDM) is one of the most widely used die-making processes especially in aerospace, automobile and electronics industries. The profile manufactured by EDM process should be dimensionally and geometrically accurate apart from good finish. This expectation is very much important as the die manufactured from EDM process is subjected to subsequent mass production. The material normally selected for die making will be superior in quality and hence time and cost of production will also be high. Selection of optimum EDM parameters may reduce the machining time along with maintaining required surface finish and dimensional accuracy. So there is a need to develop a technique for selecting the optimal EDM parameters to achieve the desired performance measures. In the present work, a recently developed Firefly Algorithm (FA) was implemented in the developed mathematical model based on the experiments conducted on an EDM. Investigations are also carried out to study the effect of EDM parameters such as current and pulse-on time on the surface roughness and machining time. The optimized machining parameters and the developed empirical relations are validated by confirmatory experiments. Machining parameters limits and desired surface finish are considered as practical constraints for both experimental and theoretical approaches. The predicted and actual machining time and surface roughness values reveals that FA is very much suitable for solving machining parameters optimization problems.