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J Duszczyk - One of the best experts on this subject based on the ideXlab platform.

  • an electron microscopical study on the growth of tio2 ag antibacterial coatings on ti6al7nb Biomedical Alloy
    Acta Biomaterialia, 2011
    Co-Authors: B S Necula, I Apachitei, F D Tichelaar, L E Fratilaapachitei, J Duszczyk
    Abstract:

    This research was aimed at investigating the growth mechanism of TiO2–Ag antibacterial coatings during plasma electrolytic oxidation (PEO) of Ti6Al7Nb Biomedical Alloy in an electrolyte based on calcium acetate/calcium glycerophosphate bearing Ag nanoparticles. The focus was on the mechanism of incorporation of Ag nanoparticles, their distribution and chemical composition within the porous coatings using high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) imaging techniques combined with energy dispersive X-ray spectroscopy (EDX) for chemical analyses. The PEO coatings were grown using different oxidation times, 10, 30, 60, 90, 120, 180, 240 and 300 s. The electron microscopy results confirmed the formation of a porous coating with incorporated Ag nanoparticles from the initial stages of oxidation (i.e. 10 s), with further Ag incorporation as the PEO process was continued for longer durations. The Ag nanoparticles were embedded in the dense oxide layer, fused into the pore walls and on the surface of the coatings without any change in their morphology or chemistry as detected by HRTEM, SEM and EDX. Ag seems to be delivered to the sites of coating growth (where dielectric breakdown occurs) through different transport pathways, i.e. open pores, cracks and short-circuit channels.

  • An electron microscopical study on the growth of TiO2–Ag antibacterial coatings on Ti6Al7Nb Biomedical Alloy
    Acta biomaterialia, 2011
    Co-Authors: B S Necula, I Apachitei, F D Tichelaar, Lidy E. Fratila-apachitei, J Duszczyk
    Abstract:

    This research was aimed at investigating the growth mechanism of TiO2–Ag antibacterial coatings during plasma electrolytic oxidation (PEO) of Ti6Al7Nb Biomedical Alloy in an electrolyte based on calcium acetate/calcium glycerophosphate bearing Ag nanoparticles. The focus was on the mechanism of incorporation of Ag nanoparticles, their distribution and chemical composition within the porous coatings using high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) imaging techniques combined with energy dispersive X-ray spectroscopy (EDX) for chemical analyses. The PEO coatings were grown using different oxidation times, 10, 30, 60, 90, 120, 180, 240 and 300 s. The electron microscopy results confirmed the formation of a porous coating with incorporated Ag nanoparticles from the initial stages of oxidation (i.e. 10 s), with further Ag incorporation as the PEO process was continued for longer durations. The Ag nanoparticles were embedded in the dense oxide layer, fused into the pore walls and on the surface of the coatings without any change in their morphology or chemistry as detected by HRTEM, SEM and EDX. Ag seems to be delivered to the sites of coating growth (where dielectric breakdown occurs) through different transport pathways, i.e. open pores, cracks and short-circuit channels.

  • Enhanced fatigue performance of porous coated Ti6Al4V Biomedical Alloy
    Applied Surface Science, 2011
    Co-Authors: I Apachitei, Lidy E. Fratila-apachitei, Alfiero Leoni, A.c. Riemslag, J Duszczyk
    Abstract:

    Biofunctional coatings are necessary to improve integration of titanium implants in the host tissue but they may be detrimental for the implant fatigue properties. This study presents an attempt towards enhancement of the in vitro fatigue strength of plasma electrolytic oxidation coated Ti6Al4V Alloy by applying shot peening process prior to coating. The electrolytic oxidation was performed in calcium acetate and calcium glycerophosphate electrolytes that allowed formation of porous oxide coatings with high surface free energy and apatite like ability. A deformed surface layer coupled with induced residual compressive stresses seem to affect oxide growth rate and fatigue behavior of the titanium Alloy.

  • In vitro fatigue behavior of surface oxidized Ti35Zr10Nb Biomedical Alloy
    Materials Science and Engineering: C, 2011
    Co-Authors: Alfiero Leoni, I Apachitei, Lidy E. Fratila-apachitei, A.c. Riemslag, J Duszczyk
    Abstract:

    Abstract New compositions of titanium Alloys with low Young's modulus as well as multiple surface biofunctionalities are under intense research focus for Biomedical applications due to the proven ability of titanium for enhancing implant integration. This study presents the effect of plasma electrolytic oxidation coating on the fatigue response of a novel β-Ti35Zr10Nb Alloy tested under physiological conditions (Hanks' solution at 37 °C). The electrolytic oxidation was conducted in calcium acetate/calcium glycerophosphate electrolyte that allowed incorporation of Ca and P within the oxide layer with potential benefits for bone apposition. The fatigue results revealed that the presence of oxide layers decreased significantly the fatigue strength of Ti35Zr10Nb Alloy relative to uncoated condition. The specific coating morphology featuring interconnected micropores, microcracks, a scalloped coating/substrate interface, as well as the ceramic nature of the oxide layer was identified as the main factors responsible for the lower fatigue performance of the coated titanium Alloy.

Thierry Gloriant - One of the best experts on this subject based on the ideXlab platform.

  • How a new strain transformable titanium-based Biomedical Alloy can be designed for balloon expendable stents
    Materialia, 2020
    Co-Authors: D.m. Gordin, D. Laillé, Frederic Prima, Thierry Gloriant
    Abstract:

    Although largely used for numerous medical devices, the current titanium medical grades are not adapted for the manufacture of balloon expandable vascular stents due to their low plastic deformation abilities compared to stainless steels and cobalt-chromium Alloys. In this study, a new biocompatible Ti-16Nb-8Mo Alloy (wt.%) was designed with the objective to obtain large ductility and high strain hardening. In the Alloy, a massive twinning and strain-induced martensitic transformation were observed to accommodate the plastic deformation leading to a very large plastic deformation since more than 45% of elongation at fracture were reached by tensile test. This huge plasticity, unusual for titanium Alloys, is due to a complex deformation mechanism implying TWinning Induced Plasticity (TWIP) and Transformation Induced Platicicy (TRIP) effects, which were particularly investigated in such strain transformable Alloy by electron backscattering diffraction (EBSD), by transmission electron microscopy (TEM) and by in-situ tensile test under synchrotron beam (SXRD). © 2020 Acta Materialia Inc.

  • Electrochemical characterization of the superelastic (Ti‐Zr)‐Mo‐Sn Biomedical Alloy displaying a large recovery strain
    Materials and Corrosion, 2017
    Co-Authors: M. F. Ijaz, D.m. Gordin, S.i. Drob, P. Osiceanu, M. Marcu, H. Y. Kim, S. Miyazaki, Cora Vasilescu, Thierry Gloriant
    Abstract:

    International audienceIn this work, the new (Ti-Zr)-1.5Mo-3Sn Biomedical Alloy showing a large superelastic recovery strain of 7% and Young's modulus of 60GPa was characterized and compared with CP Ti and Ti-6Al-4V Alloys currently used in medicine. The microstructure of the new (Ti-Zr)-1.5Mo-3Sn Alloy consists of single phase (XRD and optical microscopy results). The new Alloy has a relatively thick (7.0nm) native passive film mainly formed by protective TiO2, ZrO2, MoO2, and SnO2 oxides (XPS data). The electrochemical parameters for the new Alloy have more favorable values than those of CP Ti, and Ti-6A-4V Alloy, namely a nobler electrochemical behavior. The corrosion current density and rate of the (Ti-Zr)-1.5Mo-3Sn Alloy are about 7 times lower and the polarization resistance is about 5 times higher than those obtained for the comparing metallic Biomedical materials. Electrochemical impedance spectra proved that the new Alloy presents the most insulating and protective passive film out of the three studied materials

  • Surface Characterization, Corrosion Resistance and in Vitro Biocompatibility of a New Ti-Hf-Mo-Sn Alloy
    Materials, 2016
    Co-Authors: M. F. Ijaz, Thierry Gloriant, A. Cimpean, P. Osiceanu, Cora Vasilescu, Doina-margareta Gordin, Raluca Ion, S.i. Drob
    Abstract:

    A new superelastic Ti-23Hf-3Mo-4Sn Biomedical Alloy displaying a particularly large recovery strain was synthesized and characterized in this study. Its native passive film is very thick (18 nm) and contains very protective TiO2, Ti2O3, HfO2, MoO2, and SnO2 oxides (XPS analysis). This Alloy revealed nobler electrochemical behavior, more favorable values of the corrosion parameters and open circuit potentials in simulated body fluid in comparison with commercially pure titanium (CP-Ti) and Ti-6Al-4V Alloy taken as reference biomaterials in this study. This is due to the favorable influence of the Alloying elements Hf, Sn, Mo, which enhance the protective properties of the native passive film on Alloy surface. Impedance spectra showed a passive film with two layers, an inner, capacitive, barrier, dense layer and an outer, less insulating, porous layer that confer both high corrosion resistance and bioactivity to the Alloy. In vitro tests were carried out in order to evaluate the response of Human Umbilical Vein Endothelial Cells (HUVECs) to Ti-23Hf-3Mo-4Sn Alloy in terms of cell viability, cell proliferation, phenotypic marker expression and nitric oxide release. The results indicate a similar level of cytocompatibility with HUVEC cells cultured on Ti-23Hf-3Mo-4Sn substrate and those cultured on the conventional CP-Ti and Ti-6Al-4V metallic materials.

  • Design of a nitrogen-implanted titanium-based superelastic Alloy with optimized properties for Biomedical applications
    Materials Science and Engineering: C, 2013
    Co-Authors: D.m. Gordin, Denis Busardo, A. Cimpean, C. Vasilescu, Daniel Höche, S.i. Drob, V. Mitran, Maryline Cornen, Thierry Gloriant
    Abstract:

    In this study, a superelastic Ni-free Ti-based Biomedical Alloy was treated in surface by the implantation of nitrogen ions for the first time. The N-implanted surface was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and secondary ion mass spectroscopy, and the superficial mechanical properties were evaluated by nano-indentation and by ball-on-disk tribological tests. To investigate the biocompatibility, the corrosion resistance of the N-implanted Ti Alloy was evaluated in simulated body fluids (SBF) complemented by in-vitro cytocompatibility tests on human fetal osteoblasts. After implantation, surface analysis methods revealed the formation of a titanium-based nitride on the substrate surface. Consequently, an increase in superficial hardness and a significant reduction of friction coefficient were observed compared to the non-implanted sample. Also, a better corrosion resistance and a significant decrease in ion release rates have been obtained. Cell culture experiments indicated that the cytocompatibility of the N-implanted Ti Alloy was superior to that of the corresponding non-treated sample. Thus, this new functional N-implanted titanium-based superelastic Alloy presents the optimized properties that are required for various medical devices: superelasticity, high superficial mechanical properties, high corrosion resistance and excellent cytocompatibility.

  • Effects of thermomechanical process on the microstructure and mechanical properties of a fully martensitic titanium-based Biomedical Alloy
    Journal of the mechanical behavior of biomedical materials, 2013
    Co-Authors: W. Elmay, Thierry Gloriant, F. Prima, B. Bolle, Y. Zhong, Etienne Patoor, P. Laheurte
    Abstract:

    Thermomechanical treatments have been proved to be an efficient way to improve superelastic properties of metastable β type titanium Alloys through several studies. In this paper, this treatment routes, already performed on superelastic Alloys, are applied to the Ti-24Nb Alloy (at%) consisting of a pure martensite α′′ microstructure. By short-time annealing treatments performed on the heavily deformed material, an interesting combination of a large recoverable strain of about 2.5%, a low elastic modulus (35 GPa) and a high strength (900 MPa) was achieved. These properties are shown to be due to a complex microstructure consisting of the precipitation of nanoscale (α+ω) phases in ultra-fine β grains. This microstructure allows a superelastic behavior through stress-induced α′′ martensitic transformation. In this study, the microstructures were characterized by X-ray diffraction and transmission electron microscopy and the evolution of the elastic modulus and the strain recovery as a function of the applied strain was investigated through loading-unloading tensile tests.

Hitoshi Hamanaka - One of the best experts on this subject based on the ideXlab platform.

  • mechanical properties of the binary titanium zirconium Alloys and their potential for Biomedical materials
    Journal of Biomedical Materials Research, 1995
    Co-Authors: Equo Kobayashi, Shigeru Matsumoto, Hisashi Doi, Takayuki Yoneyama, Hitoshi Hamanaka
    Abstract:

    Mechanical properties of titanium-zirconium binary Alloys were investigated in order to reveal their possible use for new Biomedical materials and to collect useful data for Alloy design through a hardness test, a tensile test, and optical microscopy. The hardness of the Alloy containing 50% zirconium was approximately 2.5 times as large as the hardness of pure titanium and pure zirconium. Tensile tests showed a similar tendency. No changes between hardness of as cast specimens and as homogenized specimens were observed, nor were changes in microstructures noted. Comparisons between the Ti-6Al-4V Alloy and the Ti-Zr-6Al-4V Alloy indicated that a titanium-zirconium Alloy could provide a base material for a new Biomedical Alloy. From these results, it was concluded that new Alloys for Biomedical materials should be designed as titanium-zirconium base Alloys. © 1995 John Wiley & Sons, Inc.

  • Mechanical properties of the binary titanium‐zirconium Alloys and their potential for Biomedical materials
    Journal of biomedical materials research, 1995
    Co-Authors: Equo Kobayashi, Shigeru Matsumoto, Hisashi Doi, Takayuki Yoneyama, Hitoshi Hamanaka
    Abstract:

    Mechanical properties of titanium-zirconium binary Alloys were investigated in order to reveal their possible use for new Biomedical materials and to collect useful data for Alloy design through a hardness test, a tensile test, and optical microscopy. The hardness of the Alloy containing 50% zirconium was approximately 2.5 times as large as the hardness of pure titanium and pure zirconium. Tensile tests showed a similar tendency. No changes between hardness of as cast specimens and as homogenized specimens were observed, nor were changes in microstructures noted. Comparisons between the Ti-6Al-4V Alloy and the Ti-Zr-6Al-4V Alloy indicated that a titanium-zirconium Alloy could provide a base material for a new Biomedical Alloy. From these results, it was concluded that new Alloys for Biomedical materials should be designed as titanium-zirconium base Alloys.

S.i. Drob - One of the best experts on this subject based on the ideXlab platform.

  • Electrochemical characterization of the superelastic (Ti‐Zr)‐Mo‐Sn Biomedical Alloy displaying a large recovery strain
    Materials and Corrosion, 2017
    Co-Authors: M. F. Ijaz, D.m. Gordin, S.i. Drob, P. Osiceanu, M. Marcu, H. Y. Kim, S. Miyazaki, Cora Vasilescu, Thierry Gloriant
    Abstract:

    International audienceIn this work, the new (Ti-Zr)-1.5Mo-3Sn Biomedical Alloy showing a large superelastic recovery strain of 7% and Young's modulus of 60GPa was characterized and compared with CP Ti and Ti-6Al-4V Alloys currently used in medicine. The microstructure of the new (Ti-Zr)-1.5Mo-3Sn Alloy consists of single phase (XRD and optical microscopy results). The new Alloy has a relatively thick (7.0nm) native passive film mainly formed by protective TiO2, ZrO2, MoO2, and SnO2 oxides (XPS data). The electrochemical parameters for the new Alloy have more favorable values than those of CP Ti, and Ti-6A-4V Alloy, namely a nobler electrochemical behavior. The corrosion current density and rate of the (Ti-Zr)-1.5Mo-3Sn Alloy are about 7 times lower and the polarization resistance is about 5 times higher than those obtained for the comparing metallic Biomedical materials. Electrochemical impedance spectra proved that the new Alloy presents the most insulating and protective passive film out of the three studied materials

  • Electrochemical characterization of the superelastic (Ti-Zr)-Mo-Sn Biomedical Alloy displaying a large recovery strain
    Materials and Corrosion Werkstoffe und Korrosion, 2017
    Co-Authors: M. F. Ijaz, D.m. Gordin, C. Vasilescu, S.i. Drob, P. Osiceanu, M. Marcu, H. Y. Kim, S. Miyazaki, T. Gloriant
    Abstract:

    In this work, the new (Ti-Zr)-1.5Mo-3Sn Biomedical Alloy showing a large superelastic recovery strain of 7% and Young's modulus of 60GPa was characterized and compared with CP Ti and Ti-6Al-4V Alloys currently used in medicine. The microstructure of the new (Ti-Zr)-1.5Mo-3Sn Alloy consists of single phase (XRD and optical microscopy results). The new Alloy has a relatively thick (7.0nm) native passive film mainly formed by protective TiO2, ZrO2, MoO2, and SnO2 oxides (XPS data). The electrochemical parameters for the new Alloy have more favorable values than those of CP Ti, and Ti-6A-4V Alloy, namely a nobler electrochemical behavior. The corrosion current density and rate of the (Ti-Zr)-1.5Mo-3Sn Alloy are about 7 times lower and the polarization resistance is about 5 times higher than those obtained for the comparing metallic Biomedical materials. Electrochemical impedance spectra proved that the new Alloy presents the most insulating and protective passive film out of the three studied materials.

  • Deformation Mechanisms and Biocompatibility of the Superelastic Ti–23Nb–0.7Ta–2Zr–0.5N Alloy
    Shape Memory and Superelasticity, 2016
    Co-Authors: P. Castany, D.m. Gordin, A. Cimpean, C. Vasilescu, S.i. Drob, V. Mitran, T. Gloriant
    Abstract:

    In this study, we have synthesized a new Ti–23Nb–0.7Ta–2Zr–0.5N Alloy composition with the aim to obtain useful mechanical properties to be used in medicine such as high strength, good superelastic property, low modulus, and large ductility. Thus, mechanical properties including superelasticity and plasticity were investigated in relation with the different deformation mechanisms observed (stress-induced martensitic transformation, twinning and dislocation slip). On the other hand, the corrosion resistance in simulated body fluid (Ringer solution) and the in vitro cell behavior (MG63 human osteoblasts) of such Biomedical Alloy were also evaluated in order to assess its biocompatibility.

  • Deformation Mechanisms and Biocompatibility of the Superelastic Ti-23Nb-0.7Ta-2Zr-0.5N Alloy
    Shape Memory and Superelasticity, 2016
    Co-Authors: P. Castany, D.m. Gordin, A. Cimpean, C. Vasilescu, S.i. Drob, V. Mitran, T. Gloriant
    Abstract:

    In this study, we have synthesized a new Ti-23Nb-0.7Ta-2Zr-0.5N Alloy composition with the aim to obtain useful mechanical properties to be used in medicine such as high strength, good superelastic property, low modulus, and large ductility. Thus, mechanical properties including superelasticity and plasticity were investigated in relation with the different deformation mechanisms observed (stress-induced martensitic transformation, twinning and dislocation slip). On the other hand, the corrosion resistance in simulated body fluid (Ringer solution) and the in vitro cell behavior (MG63 human osteoblasts) of such Biomedical Alloy were also evaluated in order to assess its biocompatibility.

  • Surface Characterization, Corrosion Resistance and in Vitro Biocompatibility of a New Ti-Hf-Mo-Sn Alloy
    Materials, 2016
    Co-Authors: M. F. Ijaz, Thierry Gloriant, A. Cimpean, P. Osiceanu, Cora Vasilescu, Doina-margareta Gordin, Raluca Ion, S.i. Drob
    Abstract:

    A new superelastic Ti-23Hf-3Mo-4Sn Biomedical Alloy displaying a particularly large recovery strain was synthesized and characterized in this study. Its native passive film is very thick (18 nm) and contains very protective TiO2, Ti2O3, HfO2, MoO2, and SnO2 oxides (XPS analysis). This Alloy revealed nobler electrochemical behavior, more favorable values of the corrosion parameters and open circuit potentials in simulated body fluid in comparison with commercially pure titanium (CP-Ti) and Ti-6Al-4V Alloy taken as reference biomaterials in this study. This is due to the favorable influence of the Alloying elements Hf, Sn, Mo, which enhance the protective properties of the native passive film on Alloy surface. Impedance spectra showed a passive film with two layers, an inner, capacitive, barrier, dense layer and an outer, less insulating, porous layer that confer both high corrosion resistance and bioactivity to the Alloy. In vitro tests were carried out in order to evaluate the response of Human Umbilical Vein Endothelial Cells (HUVECs) to Ti-23Hf-3Mo-4Sn Alloy in terms of cell viability, cell proliferation, phenotypic marker expression and nitric oxide release. The results indicate a similar level of cytocompatibility with HUVEC cells cultured on Ti-23Hf-3Mo-4Sn substrate and those cultured on the conventional CP-Ti and Ti-6Al-4V metallic materials.

M. F. Ijaz - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Ta addition on the electrochemical behavior and functional fatigue life of metastable Ti-Zr-Nb based Alloy for indwelling implant applications
    Journal of Alloys and Compounds, 2018
    Co-Authors: M. F. Ijaz, Yulia Zhukova, Anton S. Konopatsky, S. Dubinskiy, A. A. Korobkova, Yury Pustov, Vladimir Brailovski, Sergey Prokoshkin
    Abstract:

    Abstract In this paper, the effects of Ta substitution for Nb, on the microstructure and corrosion fatigue behavior of metastable Ti-18Nb-14Zr Biomedical Alloy are investigated for the first time. For this purpose, besides previously studied ternary Ti-18Zr-14Nb Alloy, new quaternary Ti-18Zr-13Nb-1Ta (at.%) Biomedical Alloy was also synthesized by vacuum arc remelting method and subjected to thermomechanical treatment processes. The in situ electrochemical behavior and subsequent functional fatigue life of both Alloys showed a strong dependence on the composition and microstructure. The electrochemical results from the test bench demonstrated that during monotonic cycling the fatigue life of Ta-added Alloy was significantly longer than that of the Ti-18Zr-14Nb Alloy. Thus, the addition of Ta to the ternary Ti-18Zr-14Nb Alloy was found to be very effective in increasing the resistance to fatigue degradation mainly by exhibiting excellent protective passivation tendency. Based on the electrochemical evaluation and fractrographic characteristics, it is concluded that the combined effect of the stable passive film formation and higher development of a nanosubgrained structure in β phase results in the prolonged fatigue life of Ta-added Alloy.

  • Electrochemical characterization of the superelastic (Ti‐Zr)‐Mo‐Sn Biomedical Alloy displaying a large recovery strain
    Materials and Corrosion, 2017
    Co-Authors: M. F. Ijaz, D.m. Gordin, S.i. Drob, P. Osiceanu, M. Marcu, H. Y. Kim, S. Miyazaki, Cora Vasilescu, Thierry Gloriant
    Abstract:

    International audienceIn this work, the new (Ti-Zr)-1.5Mo-3Sn Biomedical Alloy showing a large superelastic recovery strain of 7% and Young's modulus of 60GPa was characterized and compared with CP Ti and Ti-6Al-4V Alloys currently used in medicine. The microstructure of the new (Ti-Zr)-1.5Mo-3Sn Alloy consists of single phase (XRD and optical microscopy results). The new Alloy has a relatively thick (7.0nm) native passive film mainly formed by protective TiO2, ZrO2, MoO2, and SnO2 oxides (XPS data). The electrochemical parameters for the new Alloy have more favorable values than those of CP Ti, and Ti-6A-4V Alloy, namely a nobler electrochemical behavior. The corrosion current density and rate of the (Ti-Zr)-1.5Mo-3Sn Alloy are about 7 times lower and the polarization resistance is about 5 times higher than those obtained for the comparing metallic Biomedical materials. Electrochemical impedance spectra proved that the new Alloy presents the most insulating and protective passive film out of the three studied materials

  • Electrochemical characterization of the superelastic (Ti-Zr)-Mo-Sn Biomedical Alloy displaying a large recovery strain
    Materials and Corrosion Werkstoffe und Korrosion, 2017
    Co-Authors: M. F. Ijaz, D.m. Gordin, C. Vasilescu, S.i. Drob, P. Osiceanu, M. Marcu, H. Y. Kim, S. Miyazaki, T. Gloriant
    Abstract:

    In this work, the new (Ti-Zr)-1.5Mo-3Sn Biomedical Alloy showing a large superelastic recovery strain of 7% and Young's modulus of 60GPa was characterized and compared with CP Ti and Ti-6Al-4V Alloys currently used in medicine. The microstructure of the new (Ti-Zr)-1.5Mo-3Sn Alloy consists of single phase (XRD and optical microscopy results). The new Alloy has a relatively thick (7.0nm) native passive film mainly formed by protective TiO2, ZrO2, MoO2, and SnO2 oxides (XPS data). The electrochemical parameters for the new Alloy have more favorable values than those of CP Ti, and Ti-6A-4V Alloy, namely a nobler electrochemical behavior. The corrosion current density and rate of the (Ti-Zr)-1.5Mo-3Sn Alloy are about 7 times lower and the polarization resistance is about 5 times higher than those obtained for the comparing metallic Biomedical materials. Electrochemical impedance spectra proved that the new Alloy presents the most insulating and protective passive film out of the three studied materials.

  • design of a novel superelastic ti 23hf 3mo 4sn Biomedical Alloy combining low modulus high strength and large recovery strain
    Materials Letters, 2016
    Co-Authors: M. F. Ijaz, D.m. Gordin, D. Laillé, P. Castany, Lorene Heraud, T. Gloriant
    Abstract:

    Abstract In this study, a new Ti-23Hf-3Mo-4Sn superelastic Alloy for Biomedical applications was elaborated and characterized. Outstanding combination of high strength (~1 GPa), low Young's modulus (55 GPa) and large recovery strain of about 4% were achieved. These mechanical properties make this newly developed Ti-23Hf-3Mo-4Sn Alloy very promising for Biomedical applications.

  • Surface Characterization, Corrosion Resistance and in Vitro Biocompatibility of a New Ti-Hf-Mo-Sn Alloy
    Materials, 2016
    Co-Authors: M. F. Ijaz, Thierry Gloriant, A. Cimpean, P. Osiceanu, Cora Vasilescu, Doina-margareta Gordin, Raluca Ion, S.i. Drob
    Abstract:

    A new superelastic Ti-23Hf-3Mo-4Sn Biomedical Alloy displaying a particularly large recovery strain was synthesized and characterized in this study. Its native passive film is very thick (18 nm) and contains very protective TiO2, Ti2O3, HfO2, MoO2, and SnO2 oxides (XPS analysis). This Alloy revealed nobler electrochemical behavior, more favorable values of the corrosion parameters and open circuit potentials in simulated body fluid in comparison with commercially pure titanium (CP-Ti) and Ti-6Al-4V Alloy taken as reference biomaterials in this study. This is due to the favorable influence of the Alloying elements Hf, Sn, Mo, which enhance the protective properties of the native passive film on Alloy surface. Impedance spectra showed a passive film with two layers, an inner, capacitive, barrier, dense layer and an outer, less insulating, porous layer that confer both high corrosion resistance and bioactivity to the Alloy. In vitro tests were carried out in order to evaluate the response of Human Umbilical Vein Endothelial Cells (HUVECs) to Ti-23Hf-3Mo-4Sn Alloy in terms of cell viability, cell proliferation, phenotypic marker expression and nitric oxide release. The results indicate a similar level of cytocompatibility with HUVEC cells cultured on Ti-23Hf-3Mo-4Sn substrate and those cultured on the conventional CP-Ti and Ti-6Al-4V metallic materials.