Electro Discharge Machining Characteristics of Mg/SiCP Metal matrix composites by Powder Metallurgy (P/M) Techniques

The objective of this work is to investigate the effects of current, pulse on time and pulse off time in Electro Discharge Machining performance on material removal rate and tool wear rate of Mg/SiCp metal matrix composites. In this work the Mg/SiCp metal matrix composite specimens were prepared by powder metallurgy route. ELEKTRA PLUS spark erosion machine was used for the purpose. Brass tool of 10 mm diameter was chosen to drill the specimens. Experiments were conducted by varying the parameters of current (I), pulse on time (ton) and pulse off time (toff). A mathematical model is developed to correlate the influences of these variables with material removal rate of workpiece and tool wear rate. Design of experiments (DOE) method and response surface methodology (RSM) techniques are implemented. An L21 orthogonal array (OA), for the three machining parameters at three levels each, was opted to conduct the experiments. The experiments were performed in a random order with three successive trials. The validity test of the fit and adequacy of the proposed models has been carried out through analysis of variance (ANOVA). KeywordEDM, Mg/SiCp composites, MRR, TWR