7. Tribological Performance Analysis of Co–Cr Alloy (Stage III)

This chapter provides an in-depth evaluation of the effectiveness of EDM in enhancing the tribological performance and cytocompatibility of medical-grade cobalt-chromium (Co–Cr) alloy. EDM is a crucial process in the manufacturing of metallic implants, as it can significantly influence both the mechanical properties and biological compatibility of the materials used. For this study, the most effective EDM process parameters identified in earlier stages (Stages I and II) were selected for further analysis. These parameters are vital for optimizing the performance of metallic implants in biomedical applications. The Co–Cr specimens used in this research were subjected to treatment using a tungsten-copper (W–Cu) electrode within a deionized water tank, serving as the dielectric medium. Different spark energy levels were applied during the EDM process, allowing for a comprehensive investigation of their effects on the material’s properties. To evaluate the cytocompatibility of the modified substrates, the MTT assay was conducted. This assay is a well-established method that measures cell viability by assessing the metabolic activity of cells after exposure to the substrates. By analyzing the results of the MTT assay, we can determine how well the material supports cell growth and proliferation, which is crucial for successful implantation. In addition to cytocompatibility, the wear rate and coefficient of friction of the substrates were assessed using a pin-on-disk tribometer. This method provides valuable insights into the tribological performance of the Co–Cr alloy, specifically its resistance to wear and friction under simulated physiological conditions. The experimental setup and operational parameters of the EDM machine are illustrated in Fig. 7.1, providing a visual reference for the arrangement used throughout the study. This comprehensive approach allows for a thorough understanding of how EDM treatments can optimize Co–Cr alloys for medical applications, ensuring both durability and biocompatibility in implantable devices.