Investigation of electrochemical discharge machining process variables during μ-drilling on stir casted novel Zn/(Ag plus Fe)-MMC for biomedical applications

Stainless steel, titanium alloy, and cobalt have long-term risks when used as metallic implants. Zinc is essential component of human body and can be used for metallic implants. The research presents the fabrication of novel hybrid Zn/(Ag + Fe)-MMC using stir casting method, analysis of microstructural and mechanical properties of fabricated MMC specimen. Electrochemical Discharge Machining (ECDM) was employed for the mu-drilling on the fabricated MMC. The effect of ECDM process variables like supply voltage, peak current, pulse-on-time, pulse-off-time, feed rate and electrolyte concentration on material removal rate (MRR), overcut (OC) and tool wear (TW) were identified during mu-drilling. Experiments had been performed based on the one factor-at-a-time approach. From the experiments it was found that MRR, OC and TW increase as supply voltage, peak current, pulse-on-time, electrolyte concentration increase and decrease as pulse-off-time increases. An increment in feed rate increases the MRR and TW but overcut decreases. Scanning electron microscopy (SEM) analysis at maximum MRR condition shows rough surface finish and ovality in mu-drilled hole. Whereas high circularity and uniform drilling attributes were obtained along the whole depth at minimum OC condition.