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[EN] Surfaces engineering on titanium biomedical alloys aiming for improving bone regeneration, healing periods and increasing lifetime needs fora fundamental understanding of the electrochemical reactions occurring at the interface biomaterial/human fluid. There, electrochemical corrosion plays an important role in implant-tissue interaction. The aim of this study is to investigate the effect of different TiO2 surfaces and nanotubes on a Ti6Al4V ELI in their electrochemical corrosion resistance by different electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization). The electrochemical behaviour of native, anodized, nanotubular and annealed nanotubular surfaces were investigated in 1 M NaCl solution. The nanotubular topography was obtained by electrochemical oxidation and the annealing treatment allowed at changing the crystalline structure of the oxides. The nanotube morphology, chemical composition, and structure was studied by Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray diffraction and Transmission Electron Microscopy respectively. The results show that the anodic oxidation treatment creates a nanotubular topography that increases the surface area and changes the surface chemical composition. The electrochemical corrosion resistance decreased on the as-formed TiO2 tubes compared to the native oxide layer, due to higher surface area and amorphous crystal structure of the passive film. After annealing treatment, the fluoride ions are eliminated, and nanotubular resistance is enhanced through anatase stabilization.

[EN] Surfaces engineering on titanium biomedical alloys aiming for improving bone regeneration, healing periods and increasing lifetime needs fora fundamental understanding of the electrochemical reactions occurring at the interface biomaterial/human fluid. There, electrochemical corrosion plays an important role in implant-tissue interaction. The aim of this study is to investigate the effect of different TiO2 surfaces and nanotubes on a Ti6Al4V ELI in their electrochemical corrosion resistance by different electrochemical techniques (open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization). The electrochemical behaviour of native, anodized, nanotubular and annealed nanotubular surfaces were investigated in 1 M NaCl solution. The nanotubular topography was obtained by electrochemical oxidation and the annealing treatment allowed at changing the crystalline structure of the oxides. The nanotube morphology, chemical composition, and structure was studied by Field Emission Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-ray diffraction and Transmission Electron Microscopy respectively. The results show that the anodic oxidation treatment creates a nanotubular topography that increases the surface area and changes the surface chemical composition. The electrochemical corrosion resistance decreased on the as-formed TiO2 tubes compared to the native oxide layer, due to higher surface area and amorphous crystal structure of the passive film. After annealing treatment, the fluoride ions are eliminated, and nanotubular resistance is enhanced through anatase stabilization.

This paper presents the study of the tribological behavior, rigidity and hardness, of the Ti6Al4V ELI alloy surface, after the performance of a glow discharge nitriding process at 450, 480 and 520 °C. The tribological pair used was metal-metal (Ti6Al4V ELI pin - Ti6Al4V ELI pre-treated disc) for the respective calculation of the coefficient of friction. Nanoindentation tests were performed with an ultra-high hardness tip with a known stiffness modulus, which provided the average hardness and Young's modulus in GPa according to ISO 14577 and ASTM G99-95 standards, respectively. Also, for the characterization of the substrate, electronic scanning microscopy, atomic force microscopy, and X-ray diffraction were used, to obtain, thus, important elasti-plastic behavioral characteristics, before and after the glow discharge plasma nitriding process was applied to the alloy., En este trabajo se estudió el comportamiento tribológico, la rigidez y dureza, de la superficie de la aleación Ti6Al4V ELI después de llevar a cabo un tratamiento de nitruración por descarga intensa de plasma a temperaturas de 450, 480 y 520 °C. El par tribológico empleado fue metal-metal (pin de Ti6Al4V ELI - disco de Ti6Al4V ELI con tratamiento) para el respectivo cálculo del coeficiente de fricción. Los ensayos de nanoindentación se realizaron con una punta de ultra alta dureza de módulo de rigidez conocido, que permitió obtener la dureza promedio y el módulo de Young en GPa, de acuerdo con las normas ISO 14577 y ASTM G99-95 respectivamente. Para la caracterización del sustrato, se empleó microscopia electrónica de barrido, microscopia de fuerza atómica y difracción de rayos X, obteniendo así características importantes del comportamiento elástico-plástico, antes y después de aplicarse la nitruración a la aleación por descarga intensa de plasma

Current mechanical forming processes used in the production of surgical Ti6Al-4V ELI devices create an undesired microstructural effect that reduces the mechanical properties of the material, thus affecting its performance while in service. In this work we study the microstructural effect that take place in the cutting pro- cess of Ti-6Al4V ELI with the goal of selecting the best available cutting conditions for Quirúrgicos Especial- izados company needs. The cutting process offers two conditions to control rotation and lineal feed speed in the cutting tool. For this work we cut six samples of Ti- 6Al-4V ELI, each sample had different conditions to be metallographically analyzed via optical microscopy. We observed a modification on the Ti-6Al-4V ELI microstruc- ture and a qualitative effect on the mechanical proper- ties have been estimated, allowing the selection of the more efficient conditions in the cutting process.

This paper presents the study of the tribological behavior, rigidity and hardness, of the Ti6Al4V ELI alloy surface, after the performance of a glow discharge nitriding process at 450, 480 and 520 °C. The tribological pair used was metal-metal (Ti6Al4V ELI pin - Ti6Al4V ELI pre-treated disc) for the respective calculation of the coefficient of friction. Nanoindentation tests were performed with an ultra-high hardness tip with a known stiffness modulus, which provided the average hardness and Young's modulus in GPa according to ISO 14577 and ASTM G99-95 standards, respectively. Also, for the characterization of the substrate, electronic scanning microscopy, atomic force microscopy, and X-ray diffraction were used, to obtain, thus, important elasti-plastic behavioral characteristics, before and after the glow discharge plasma nitriding process was applied to the alloy., En este trabajo se estudió el comportamiento tribológico, la rigidez y dureza, de la superficie de la aleación Ti6Al4V ELI después de llevar a cabo un tratamiento de nitruración por descarga intensa de plasma a temperaturas de 450, 480 y 520 °C. El par tribológico empleado fue metal-metal (pin de Ti6Al4V ELI - disco de Ti6Al4V ELI con tratamiento) para el respectivo cálculo del coeficiente de fricción. Los ensayos de nanoindentación se realizaron con una punta de ultra alta dureza de módulo de rigidez conocido, que permitió obtener la dureza promedio y el módulo de Young en GPa, de acuerdo con las normas ISO 14577 y ASTM G99-95 respectivamente. Para la caracterización del sustrato, se empleó microscopia electrónica de barrido, microscopia de fuerza atómica y difracción de rayos X, obteniendo así características importantes del comportamiento elástico-plástico, antes y después de aplicarse la nitruración a la aleación por descarga intensa de plasma

Current mechanical forming processes used in the production of surgical Ti6Al-4V ELI devices create an undesired microstructural effect that reduces the mechanical properties of the material, thus affecting its performance while in service. In this work we study the microstructural effect that take place in the cutting pro- cess of Ti-6Al4V ELI with the goal of selecting the best available cutting conditions for Quirúrgicos Especial- izados company needs. The cutting process offers two conditions to control rotation and lineal feed speed in the cutting tool. For this work we cut six samples of Ti- 6Al-4V ELI, each sample had different conditions to be metallographically analyzed via optical microscopy. We observed a modification on the Ti-6Al-4V ELI microstruc- ture and a qualitative effect on the mechanical proper- ties have been estimated, allowing the selection of the more efficient conditions in the cutting process.