Electrochemical Machining of D2 Steel: Parameter Optimization Using KBr and NaNO3 Electrolytes

This study investigates the influence of process parameters on the material removal rate, surface roughness, tool wear rate, and overcut in the electrochemical machining (ECM) process using two electrolytes, sodium nitrate (NaNO3) and potassium bromide (KBr), at varying voltage and feed rates. A total of 19 experimental runs were conducted to explore the effects of these parameters on ECM performance. The results were analyzed using Design Expert software to develop predictive models for each output, with R2 values calculated to assess model accuracy. The MRR model, with an R2 value of 0.957, showed a strong correlation with process parameters, indicating that KBr, 20 V voltage, and a feed rate of 0.12 mm/min yielded the highest MRR. The surface roughness model (R2 = 0.876) indicated that KBr produced higher roughness compared to NaNO3. The TWR model, with an R2 value of 0.901, revealed that NaNO3caused more tool wear than KBr. The overcut model (R2 = 0.924) demonstrated that lower voltages resulted in higher overcut values, with KBr exhibiting lower overcut than NaNO3. Multi-response optimization using Design Expert identified the optimal parameters—20 V voltage, 0.119 mm/min feed rate, and KBr electrolyte—achieving the highest desirability score of 0.806. This research provides valuable insights into the optimization of ECM parameters to enhance machining efficiency. Further investigations could refine the models and extend the understanding of ECM process dynamics.