Electrical discharge machining of titanium alloy using diatomite powder-mixed dielectric fluid based on response surface methodology

Abstract

In this investigation, variables such as diatomite powder concentration, spark duration and discharge current are varied to study the impact on material removal rate (MRR) on titanium alloy and tool wear rate (TWR). Totally 20 run of different parameter combinations are formulated using central composite design. It is found from the obtained results that there is a linear increasing pattern for MRR with variation in I, spark duration and powder concentration. Moreover, TWR exhibited inverse effect with addition of diatomite powder and linear uptrend with change in pulse energy and sparking period. In sequence, desirability function method is used to satisfy two conflicting metrics (Maximum MRR and Minimum TWR) and the obtained combination of variables are I = 24 amps, Ton = 8 μs and powder concentration = 8 gm/litre. Desirability value of 0.680 obtained for the conflicting performance characteristics.