scholarly journals Role of Vanadium Additions on the Corrosion Mitigation of Ti-6Al-xV Alloy in Simulated Body Fluid

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 903 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Sameh A. Ragab ◽  
Hany S. Abdo
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclic Potentiodynamic Polarization ◽  
Elemental Analyses ◽  
Corrosion Behaviors

The manufacturing of different Ti-6Al-xV (x = 2, 4, 6, and 8 wt.%) alloys using a mechanical alloying technique was reported. The corrosion behaviors of these newly fabricated alloys after 1, 24, and 48 h exposure to a simulated body fluid (SBF) were assessed using cyclic potentiodynamic polarization, electrochemical impedance spectroscopy, and chronoamperometric measurements. Surface morphology and elemental analyses after corrosion for 48 h in SBF were reported using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) examinations. An X-ray diffraction investigation characterized the phase analyses. All results indicated that the increase of V content significantly decreases both uniform and pitting corrosion. This effect also increases with prolonging the immersion time to 48 h before measurement.

scholarly journals Evaluación de la degradación de superficies de fluorapatita mediante técnicas electroquímicas. (Degradation Assessment of Fluorapatite Surfaces using Electrochemical Techniques)

2015 ◽  
Vol 6 (1) ◽  
pp. 33 ◽  
Author(s):  
L. J. Reyes Jaimes ◽  
H. A. González Romero ◽  
A. Sandoval Amadora ◽  
D. Y. Peña Ballesteros ◽  
H. A. Estupiñán Durán
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Active Surface ◽  
Apatite Formation ◽  
X Ray ◽  
Cathodic Electrodeposition ◽  
High Concentrations

ResumenSe evaluó el efecto del pH de fluido corporal simulado en la formación de apatitas y en la degradación de superficies de la aleación Ti6Al4V recubiertas con Fosfato de Calcio mediante la técnica de lectrodeposición catódica. Como variables de estudio se tomaron el pH del fluido corporal simulado y el tiempo de inmersión de los recubrimientos. Mediante microscopia electrónica de barrido, espectroscopia de energía dispersiva, difracción de rayos X y absorción atómica se pudo corroborar la formación de apatitas, y la degradación de los recubrimientos se evaluó mediante Espectroscopia de impedancia electroquímica y curvas de polarización potenciodinámicas. Los resultados obtenidos muestran que los recubrimientos tenían altas concentraciones de Fluorapatita (Ca5(PO4)3F) y que su formación se ve favorecida a medida que el pH del fluido corporal simulado y el tiempo de inmersión aumenta. Por otra parte, se obtuvo que las muestras evaluadas a pH de 7,2 son menos estables termodinámicamente, sin embargo, las evaluadas a 7,6 presentan una superficie más activa, por lo que se obtiene una mayor velocidad de degradación. AbstractThe pH eect of a Simulated Body Fluid in the apatite formation and the degradation of the Ti6Al4V alloy surfaces, coated by calcium phosphate obtained through cathodic electrodeposition was evaluated. The simulated body fluid pH and the coating immersion time were taken as variables. The formation of apatite was corroborated by Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X Ray Diraction and Atomic Absorption Techniques. The coating degradation was assessed by the Electrochemical Impedance Spectroscopy and the Potential Dynamic Polarization Curves. The results have shown that the coatings had high concentrations of fluorapatite (Ca5(PO4)3F) and its formation was favored as the simulated body fluid pH and the immersion time increases. Moreover, it was found that the coatings samples evaluated at pH 7.2 were less thermodynamically steady, however, the evaluated coating at pH 7.6 exhibited a more active surface, so that a higher rate of degradation is obtained.

scholarly journals Beneficial Effects of Vanadium Additions on the Corrosion of Ti6AlxV Alloys in Chloride Solutions

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 264 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Hany S. Abdo ◽  
Nabeel H. Alharthi
Keyword(s):  
Electron Microscopy ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Test Medium ◽  
X Ray ◽  
Beneficial Effects ◽  
Cyclic Potentiodynamic Polarization ◽  
Scanning Electron

The beneficial effects of V addition on the corrosion of a newly manufactured Ti6AlxV (x = 2 wt %, 4 wt %, 6 wt %, and 8 wt %) alloys after various exposure periods in 3.5% NaCl solutions were reported. The Ti6AlxV were produced from their raw powders using mechanical alloying. Several electrochemical techniques such as electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and potentiodynamic current versus time at 300 mV experiments were conducted. The surface morphology and the elemental analysis were performed using scanning electron microscopy and energy dispersive X-ray analyses. All results were consistent with each other revealing that the increase of V content increases the resistance of the alloys against corrosion. The increase of corrosion resistance was achieved by the role of V in decreasing the rate of corrosion as a result of the formation of oxide films on the surface of the alloys. This effect was found to increase with prolonging the immersion time of the Ti6AlxV alloys in the test medium from 1 h to 24 h and further to 48 h.

In Vitro Study of Microplasma Sprayed Hydroxyapatite Coatings in Simulated Body Fluid

2009 ◽  
Vol 79-82 ◽  
pp. 815-818 ◽  
Author(s):  
Qiu Ying Zhao ◽  
Ding Yong He ◽  
Xiao Yan Li ◽  
Jian Min Jiang
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Carbonate Apatite ◽  
In Vitro Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Phases ◽  
Hydroxyapatite Coatings ◽  
Vitro Test

Hydroxyapatite (HA) coatings were deposited onto Ti6Al4V substrate by microplasma spraying (MPS) in the current research. The morphology, phase compositions, and percentage of crystallinity of the coatings were characterized by means of scanning electron microscopy (SEM) and X-ray diffraction. An in vitro evaluation by soaking the coatings in simulated body fluid (SBF) for up to 14 days was conducted aiming at the evaluation of their bioactivity. Results from the present investigation suggest that microplasma sprayed HA coatings exhibited certain roughness, pores, and microcracks. Thermal decomposition existed in the coatings where HA, α-TCP，β-TCP, amorphous phases, and CaO-exclusive impurities were observed. The in vitro test indicated that HA coatings deposited by MPS possessed better bioactivity and stability. A layer of carbonate-apatite covered most of the coating surface, which did not exhibit significant spalling after incubation in SBF.

scholarly journals The Atomic-Scale Interaction of Bioactive Glasses with Simulated Body Fluid

2005 ◽  
Vol 480-481 ◽  
pp. 21-26 ◽  
Author(s):  
L.J. Skipper ◽  
F.E. Sowrey ◽  
D.M. Pickup ◽  
R.J. Newport ◽  
K.O. Drake ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Sol Gel ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Bioactive Glasses ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The formation of a carbonate-containing hydroxyapatite, HCAp, layer on bioactive calcium silicate sol-gel glass of the formula (CaO)0.3(SiO2)0.7 has been studied in-vitro in Simulated Body Fluid (SBF). Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES), X-ray diffraction (XRD), and solid state nuclear magnetic resonance (NMR) measurements have been performed with results showing the formation of a significantly amorphous HCAp layer after less than 5 hours in solution.

scholarly journals Effect of Zn Content on Orthopedic Mg aAlloy as Smart Implant

2020 ◽  
Vol 71 (6) ◽  
pp. 96-110
Author(s):  
Omyma Ramadan Mohammed Khalifa ◽  
Abdel-Wahab Abd Elhamid Ali ◽  
Aisha Kassab ◽  
Amal Hemida Tilp ◽  
Marwa Mohamed Mohamed Mohamed Esmail
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Orthopedic Implants ◽  
X Ray Diffraction ◽  
Electro Deposition ◽  
X Ray ◽  
Zn Content ◽  
The Media

In recent years, smart implants take the most attention in the field of bone manufacturing. Our study seeks to develop the biodegradability of Mg alloys to use orthopedic implants for the biomedical applications to avoid post removal of the implant. Mg and Zn are very important to human body and have no toxicity. Mg - 6% wt Zn biodegradability is studied in simulated body fluid for two and four weeks. Four electro-deposition bathes are used to deposit a coat on the substrate to improve the corrosion resistance of this alloy in the media of simulated body fluid. The following analyses were studied to emphasize the research aim. Scanning electron microscope (SEM), Energy dispersive X-Ray (EDX) analysis shows the surface morphology and the elements of the coat phases components. The results also confirmed by X-Ray diffraction Pattern (XRD) that show the phases that confirmed the formation of hydroxyapatite HA phase, Fourier-Transform Infrared Spectroscopy (FTIR) to investigate the functional groups of the phases coats that confirm the formation of hydroxyapatite and the electrochemical measurements that investigate the improvement of corrosion resistance. The results indicated that the fourth bath gives the best coat and four weeks immersion gives more corrosion resistance than two weeks.

Fast Synthesis of Rutile/Apatite Core/Shell Structured Photocatalyst in Simulated Body Fluid

2012 ◽  
Vol 465 ◽  
pp. 66-71 ◽  
Author(s):  
Fu Zhi Shi ◽  
Yao Gang Li ◽  
Hong Zhi Wang ◽  
Qing Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Transmission Electron ◽  
Tio2 Microspheres

The core/shell structured rutile/apatite was prepared by soaking rutile TiO2 (R-TiO2) microspheres into a simulated body fluid (SBF) only for 1 day. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) and N2 adsorption measurements. XRD showed that the apatite content increased with prolonging the soaking time or increasing the SBF concentration. TEM and EDX demonstrated that apatite had been coated on the surface of R-TiO2 microspheres successfully. HRTEM indicated that the lattice spacings of 0.27 nm and 0.32 nm were assigned to (211) plane of apatite and (101) plane of R-TiO2, respectively.

A Biomimetic Method of Hydroxyapatite Powders Synthesized in Simulated Body Fluid

2005 ◽  
Vol 297-300 ◽  
pp. 1371-1375
Author(s):  
Feng Wang ◽  
Mu Sen Li
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Simulated Body Fluid ◽  
Transmission Electron Microscope ◽  
Body Fluid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infra Red ◽  
Biomimetic Method

Hydroxyapatite (HA) powders were directly synthesized in simulated body fluid (SBF) at 37°C, without the need for high-temperature calcified. These powders were found to contain trace amount of CO32-, Cl-, Na+ and K+ impurities, originated from the of SBF solutions during their deposition. The characterizations of the synthesized HA powders were performed by X-ray diffraction (XRD), Fourier-transformed infra-red spectroscopy (FTIR) and Transmission electron microscope (TEM). The experimental results showed that the HA synthesized by the SBF route might be more close to that human bone in structure and compositions. Furthermore, the processes flow for HA synthesis was optimized and the synthesized mechanism was also discussed.

scholarly journals Atomic Layer Deposition of aTiO2 Layer on Nitinol and Its Corrosion Resistance in a Simulated Body Fluid

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 659
Author(s):  
Rebeka Rudolf ◽  
Aleš Stambolić ◽  
Aleksandra Kocijan
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Atomic Layer Deposition ◽  
Body Fluid ◽  
Electrochemical Impedance ◽  
Atomic Layer ◽  
Tio2 Layer ◽  
High Tendency ◽  
X Ray ◽  
Layer Deposition

Nitinol is a group of nearly equiatomic alloys composed of nickel and titanium, which was developed in the 1970s. Its properties, such as superelasticity and Shape Memory Effect, have enabled its use, especially for biomedical purposes. Due to the fact that Nitinol exhibits good corrosion resistance in a chloride environment, an unusual combination of strength and ductility, a high tendency for self-passivation, high fatigue strength, low Young’s modulus and excellent biocompatibility, its use is still increasing. In this research, Atomic Layer Deposition (ALD) experiments were performed on a continuous vertical cast (CVC) NiTi rod (made in-house) and on commercial Nitinol as the control material, which was already in the rolled state. The ALD deposition of the TiO2 layer was accomplished in a Beneq TFS 200 system at 250 °C. The pulsing times for TiCl4 and H2O were 250 ms and 180 ms, followed by appropriate purge cycles with nitrogen (3 s after the TiCl4 and 2 s after the H2O pulses). After 1100 repeated cycles of ALD depositing, the average thickness of the TiO2 layer for the CVC NiTi rod was 52.2 nm and for the commercial Nitinol, it was 51.7 nm, which was confirmed by X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope (SEM) using Energy-dispersive X-ray (EDX) spectroscopy. The behaviour of the CVC NiTi and commercial Nitinol with and without the TiO2 layer was investigated in a simulated body fluid at body temperature (37 °C) to explain their corrosion resistance. Potentiodynamic polarisation measurements showed that the lowest corrosion current density (0.16 μA/cm2) and the wider passive region were achieved by the commercial NiTi with TiO2. Electrochemical Impedance Spectroscopy measurements revealed that the CVC NiTi rod and the commercial Nitinol have, for the first 48 h of immersion, only resistance through the oxide layer, as a consequence of the thin and compact layer. On the other hand, the TiO2/CVC NiTi rod and TiO2/commercial Nitinol had resistances through the oxide and porous layers the entire immersion time since the TiO2 layer was formatted on the surfaces.

scholarly journals Supramolecular Association between γ-Cyclodextrin and Preyssler-Type Polyoxotungstate

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5126
Author(s):  
Nathalie Leclerc ◽  
Mohamed Haouas ◽  
Clément Falaise ◽  
Serge Al Bacha ◽  
Loïc Assaud ◽  
...  
Keyword(s):  
1H Nmr Spectroscopy ◽  
Organic Molecule ◽  
Electrochemical Impedance ◽  
Weak Interactions ◽  
Supramolecular Compound ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Inorganic Anion ◽  
X Ray ◽  
Elemental Analyses

The development of hybrid materials based on polyoxometalates constitutes a strategy for the design of multifunctional materials. The slow evaporation of an aqueous solution of [NaP5W30O110]14− in the presence of γ-Cyclodextrin (γ-CD) led to the crystallization of a K6Na8{[NaP5W30O110]•(C48H80O40)}•23H2O (NaP5W30•1CD) supramolecular compound, which was characterized by single-crystal X-ray diffraction, IR-spectroscopy, thermogravimetric and elemental analyses. Structural analysis revealed the formation of 1:1 {[NaP5W30O110]•[γ-CD]}14− adduct in the solid state. Studies in solution by cyclic voltammetry, electrochemical impedance spectroscopy, 1H NMR spectroscopy, and 31P DOSY, have demonstrated weak interactions between the inorganic anion and the macrocyclic organic molecule.

In Vitro Bioactivity of Composite of Nanophase Titania/Bioactive Glass-Ceramic in Simulated Body Fluid

2005 ◽  
Vol 288-289 ◽  
pp. 171-174
Author(s):  
Hui Wang ◽  
Bang Cheng Yang ◽  
Qi Feng Yu ◽  
Dayi Wu ◽  
Xing Dong Zhang
Keyword(s):  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Glass Ceramic ◽  
Body Fluid ◽  
Mechanical Analysis ◽  
Apatite Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Biomechanical Compatibility

Titania ceramics is lack of bone-bonding ability even if it has excellent biocompatibility. Recently, it is even found that the nanophase titania ceramics could enhance the proliferation of osteoblasts. If the bone-bonding ability of this material is improved, it would be a potential bone replacement material. Bioactive glass-ceramic (BGC) is provided with the best bioactivity in biomaterials. In this study, the apatite formation ability and the mechanic properties of titania ceramic were investigated by the accession of BGC. Four samples: TiO2 ceramic, TiO2 +10%BGC, TiO2 +20%BGC and BGC were prepared respectively. These ceramics were exposed to a simulated body fluid (SBF) for 7, 14 and 21d. Scanning electron microscopy (SEM), energy dispersive X-ray detector (EDX) and thin film X-ray diffraction (TF-XRD) results showed that the apatite formation of the ceramics was improved by adding BGC into nanophase titania ceramic. The mechanical analysis showed the biomechanical compatibility was also improved by adding BGC into nanophase titania ceramic.

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