Abstract Pure titanium and various alloys, such as Ti-6Al-4V, are widely used as biomaterials. In this application, surface finish conditions, topography, and surface reactivity determine excellent cellular adhesion and osseointegration characteristics. The study evaluated the influence of four surface finishing treatments (sanding #120, 600, 1200, and polished with 3 µm alumina paste) and three shapes (concave, convex, and flat) on the corrosion resistance of Ti-6Al-4V at 37 °C in simulated body fluid (SBF) through potentiodynamic polarization and electrochemical impedance spectroscopy. The SBF's ionic composition allowed the formation of a stable passive layer with a low presence of pores on the surface. In addition, the combination of polished surface and convex shape showed the best electrochemical passive behavior.

The crystal structure of two B-type carbonated apatite samples was re-analyzed, using the data of Wilson et al (2006). By applying the least squares method for the determination of carbon and oxygen atoms, a slightly different result was obtained, suggesting that the carbonate ion is not rigorously planar

Steels employed in offshore oil and gas production are subject to a very corrosive environment. Especially the new oilfields located in pre-salt layers imply the contact of steels with high brine concentration, high temperature and presence of corrosive gas such as CO2. Besides these facts, stainless steels have to present higher mechanical properties obtained from an optimized heat treatment. In order to take into account these factors and their synergisms, on the present paper, we have chosen a factorial experimental design to study the corrosion behavior of superduplex steel UNS S32750 by electrochemical tests. The results of open circuit potential, polarization curves and electrochemical impedance were analyzed with statistical methods considering a confidence level of 95%. The factors that significantly affect the corrosion potential are the carbon dioxide and heat treatment; the corrosion current is sensitive to carbon dioxide, and the resistance of polarization is strongly affected by the CO2 content.