Bioactivity study of Co-Cr alloys doped with tantalum for biomedical applications

Abstract

Co-Cr alloys are well known because of its high wear resistance, mechanical strength and corrosion resistance due to the chromium oxide passive layer formation that protects the material surface [1].The addition of alloying elements, particularly Mo and W, improve the properties of Co-Cr bioalloys, although these materials can still be improved to meet the requirements for a biomaterial.Thus, considering that tantalum is a bioactive metal, it can be an interesting option to improve the biocompatibility properties of these alloys[2].The present study aims the synthesis and in vitro evaluation bioactivity of Co-Cr alloy doped with tantalum.The synthetized alloys were submitted to a surface treatment and subsequentlyimmersed in Simulated Body Fluid (SBF) for 28 days. The samples bioactivity was evaluated by using X- ray Diffraction (DRX), Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy (EDS) and Atomic Force Microscopy (AFM) techniques. X- ray diffraction analysisin the SBF immersed samples shown a small intensity peak characteristicof hydroxyapatite while MEV and EDS results revealeda surface structure with the presence of P, Mg, Ca and Oelements. The grain growth dynamics on the samples surfaces was observed by using AFM measurements.