ELECTRIC DISCHARGE MACHINING-INDUCED SURFACE MODIFICATION ON ADDITIVELY MANUFACTURED BIOMEDICAL TI-TA ALLOY

Abstract

In biomedical engineering there is growing demand for materials and surface treatments that improve implant performance. This study investigates die sinking and micro electrical discharge machining (EDM) as post-processing routes for additively manufactured Ti-6Al-4V alloyed with 8-wt % tantalum, a composition that shows enhanced mechanical strength and biocompatibility. Taguchi L9 and Box-Behnken designs were applied to explore the effect of current, pulse-on time, and pulse-off time in die-sinking EDM, and of capacitance, voltage, and spindle speed in micro-EDM. Responses included material removal rate, surface roughness, crater size, overcut, and micro-hardness. Statistical models showed good fit with all key responses having R² values above 0.80. Die-sinking EDM results indicated that higher current and longer pulse-on time increase material removal while simultaneously reducing surface roughness and overcut. In micro-EDM, higher capacitance and voltage improved surface smoothness and hardness without compromising geometric accuracy. The findings give clear guidelines for tuning EDM parameters to obtain surfaces that support osseointegration and long-term durability. The work therefore advances the design of titanium-based implants with improved clinical integration.