Effect of Surfactant on EDM of Low Conductivity Reaction-Bonded Silicon Carbide

Abstract

This work was focused on improving machining performance of reaction-bonded silicon carbide (RB-SiC) ceramic material using an electrical discharge machine (EDM) with the aid of surfactant. The changes of material removal rate, electrode wear ratio and surface roughness were investigated under two different surfactants, namely Span 20 and Span 80. The surfactant was mixed with carbon nanofiber (CNF) and EDM oil prior to the experiment. Then, the mixture was homogenized in an ultrasonic homogenizer for 35 minutes. In order to investigate the effect of surfactant, different weight percentages which is 0.4wt%, 0.6wt% and 0.8wt% of surfactant were used. The experimental results show that with the addition of Span 20 and Span 80, the electrode wear ratio was decreased with the increased of surfactants weight percentage. Surface finish also can be improved by adding surfactant in the dielectric fluid. The lowest surface roughness was achieved at a surfactant weight percentage of 0.4wt%. The optimum weight percentage for obtaining the highest material removal rate (MRR) was 0.6wt% for both surfactants. In comparison, CNF added with surfactant Span 80 was more effective to improve the machining efficiency of RB-SiC compared to surfactant Span 20, at the optimum weight percentage 0.6wt%.