Nacre-like Co–Cr–Mo/Ti₂O₃ coating on the Co–Cr–Mo substrate prepared using spark plasma sintering

Despite the common use of Co–Cr–Mo based prostheses in orthopedics, wider medical applications of such implants are often limited by their inherent bioinertness and inadequate adhesion to bone. A bioactive ceramic coating can improve their bonding to bone. In this study, a nacre-like Co–Cr–Mo/Ti₂O₃ coating on the Co–Cr–Mo substrate was prepared in one single step using spark plasma sintering (SPS). The microstructure, mechanical properties, and biocompatibility of the pellet were extensively studied. The lamellar Co–Cr–Mo and Ti₂O₃ layers with a thickness of several microns were alternated, resembling the “bricks‐and‐mortar” microstructure of nacre. Co–Cr–Mo consisted of γ phase, ε phase and carbide. The interfacial bonding between Co–Cr–Mo and Ti₂O₃ was strong, which is essential to achieving high ductility. The incorporation of Ti₂O₃ to form a composite coating led to improved biocompatibility, with MG63 human osteosarcoma cells cultured on the surface exhibiting faster proliferation and higher viability.