Abstract
Alloys of the Ti-Nb system are promising in the orthopedic area, due to the fact that niobium has a minimum dissolution rate, which contributes to low cytotoxicity, and is also a beta-stabilizing element, acting in decrease of the elastic modulus. On the other hand, the surface of an orthopedic implant strongly interferes in the osseointegration process, due to its direct interaction with cells, proteins and microorganisms of the biological environment. Implant degradation by mechanisms of electrochemical corrosion and mechanical wear (tribocorrosion) also depends on the surface characteristics, knowing that degradation products can affect the biological response of the patients. Due to its simplicity and low cost, electrochemical anodization technique appears as an attractive method for functionalizing metallic biomaterials surface. Therefore, this project aims to use the micro-arc oxidation (MAO) method to incorporate bioactive ions as well as ceramic particles on the surface of Ti-40Nb alloy (wt%), in order to produce osseointegrable orthopedic implants with chemical and structural functional gradients on their surface. Additionally, this work also aims to better understand the influence of the anodizing parameters on the ceramic particles distribution on the oxide films, as well as to analyze the influence of four different composition of electrolyte on the films properties, such as chemical composition, crystalline structure, elastic modulus, thickness, porosity and size of nano-micro-structures formed, as well as their degradation behavior. (AU)
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