6. In-Vitro Corrosion Investigation of Co–Cr Alloy (Stage II)

This chapter delves into the in-vitro corrosion analysis of medical-grade cobalt-chromium (Co–Cr) alloy surfaces modified through electrical discharge treatment (EDT). The study systematically varies spark energy levels and explores different dielectric environments to understand their impact on microstructural changes, surface characteristics, and overall functional behavior. Electrochemical corrosion measurements reveal that Sample 13 exhibits the highest corrosion resistance, with a remarkably low corrosion rate of 0.0003 mm/year. Hemocompatibility assessments show that Sample 13 also demonstrates minimal hemolysis and a significantly greater quantity of intact red blood cells (RBCs) compared to untreated samples. The study identifies optimal EDM parameters, including a current of 10 A, a pulse-on time of 200 µs, a pulse-off time of 60 µs, and the use of a tungsten-copper (W–Cu) electrode in deionized water. These findings underscore the potential of EDM as a powerful technique for enhancing the performance of biomedical materials in applications where corrosion resistance and biocompatibility are critical.