Surface Modification of Co–Cr Alloy for Orthopaedic Applications

This monograph focuses on the surface modification of medical-grade Co-Cr (ASTM F75) alloy using the Electrical Discharge Machining (EDM) to enhance the biological response, corrosion resistance, and surface properties of metallic implants. The aim is to improve long-term implant functionality by addressing critical challenges such as inflammatory responses, bacterial infections, wear, corrosion, and loosening, which often lead to implant failure and revision surgeries. The work is structured into three stages: in Stage I, a full factorial experimental array was designed by varying current and pulse-on-time to analyze the influence of spark energy on the Co-Cr alloy surface; in Stage II, Taguchi’s L18 orthogonal array was employed to examine the effects of discharge current, pulse-on-time, pause time, dielectric medium, and tool electrode, with corrosion reactivity assessed in biological environments using potentiodynamic techniques; in Stage III, tribological properties and in-vitro cytotoxicity were studied through wear rate and coefficient of friction tests on a pin-on-disc tribometer in ringer solution. Surface characterization using SEM, EDX, and XRD provided detailed insights into the impact of EDM on surface features. This book will serve as a valuable resource for researchers and students in biomaterials, offering guidance on recent trends and applications for enhancing implant bioactivity, adaptability, and durability.