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 y phase, e 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.