Estudo da corrosão do aço AISI 316L com adição do fosfato de cálcio depositado por oxidação eletrolítica à plasma

Abstract

316L stainless steel has been widely used as a metallic biomaterial for orthopedic and dental implants due to its excellent mechanical properties and low cost. However, one of the main limitations to its clinical use is the susceptibility to localized corrosion in physiological envi-ronments that can result in inflammation, pain and, in the worst case, implant failure. To in-crease its biocompatibility, the metal can be coated with hydroxyapatite which has a chemical composition similar to the inorganic matrix of bone. The objective of this study is to improve the corrosion behavior, biocompatibility of the metallic implant and osseointegration. Stainless steel 316L was used as a metallic substrate for the deposition of the hydroxyapatite coating performed by the electroplating technique called Plasma Electrolytic Oxidation (PEO). The samples were immersed in electrolyte solution. Then, a potential difference was applied using two configurations: a cathodic reaction during the times of 90 and 180 seconds and an anodic reaction during the times of 15 and 19 seconds. analyzed by Scanning Electron Microscopy (SEM). Furthermore, the corrosion properties of the treated surfaces of the samples were eval-uated by means of potentiodynamic polarization tests using an electrochemical corrosion cell with an electrolyte concentration equal to 3% sodium chloride (NaCl). The results obtained showed that the bioactive hydroxyapatite coatings were successfully deposited on the substrate surface and presented a relevant and uniform thickness, constituted by a stable chemical com-position.O resumo do trabalho (em inglês) deverá ser apresentado em parágrafo único e conter no máximo 3000 caracteres.