Microstructure, bioactivity and wear resistance of sintered composite Co-Cr-Mo/Bioglass® for medical implant applications

A sintered Co-Cr-Mo/Bioglass® composite coating, developed for medical implant application, is examined and compared to plasma-sprayed and sintered monolithic Co-Cr-Mo coatings. In addition to microstructure and wear resistance analysis, the bioactivities and corrosion behaviours of various coatings are assessed using simulated body fluid (SBF) immersion. The sintered Co-Cr-Mo/Bioglass® composite and monolithic Co-Cr-Mo coatings have more porous structure than the plasma sprayed Co-Cr-Mo coating. Although the Co-Cr-Mo/Bioglass® composite coating has adequate bonding between Co-Cr-Mo powder and glass particles, the wear resistance is lower than the plasma sprayed Co-Cr-Mo and Stellite 21 substrate. After SBF immersion, calcium is present on the Co-Cr-Mo/Bioglass composite coating, but not on the Co-Cr-Mo coating. It indicates the formation of an apatite layer on the Co-Cr- Mo/Bioglass composite coating and potentially better bioactivity than the monolithic coatings.