Comparison of Biocompatible Coatings Produced by Plasma Electrolytic Oxidation on cp-Ti and Ti-Zr-Nb Superelastic Alloy

The paper compares the coatings produced by plasma electrolytic oxidation (PEO) on commercially pure titanium and a novel superelastic alloy Ti-18Zr-15Nb (at. %) for implant applications. The PEO coatings were produced on both alloys in the identical pulsed bipolar regime. The properties of the coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX), potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The PEO process kinetics was modeled based on the Avrami theorem and Cottrell equation using a relaxation method. The resultant coatings contain TiO2, for both alloys, and NbO2, Nb2O5, ZrO2 for Ti-18Zr-15Nb alloy. The coating on the Ti-18Zr-15Nb alloy has a higher thickness, porosity, and roughness compared to that on cp-Ti. The values of the kinetic coefficients of the PEO process—higher diffusion coefficient and lower time constant for the processing of Ti-18Zr-15Nb—explain this effect. According to the electrochemical studies, PEO coatings on Ti-18Zr-15Nb alloy provide better corrosion protection. Higher corrosion resistance, porosity, and roughness contribute to better biocompatibility of the PEO coating on Ti-18Zr-15Nb alloy compared to cp-Ti.

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Improvement of Mechanical and Corrosion Properties of Commercially Pure Titanium Using Alumina PEO Coatings

Coatings ◽

10.3390/coatings12010029 ◽

2021 ◽

Vol 12 (1) ◽

pp. 29

Author(s):

Viorel Malinovschi ◽

Alexandru Horia Marin ◽

Catalin Ducu ◽

Sorin Moga ◽

Victor Andrei ◽

...

Keyword(s):

Plasma Electrolytic Oxidation ◽

Pure Titanium ◽

Commercially Pure Titanium ◽

Corrosion Properties ◽

Commercially Pure ◽

Electrolytic Oxidation ◽

Aluminum Oxide Layer ◽

Plasma Electrolytic ◽

Cp Ti ◽

Peo Coatings

In this study, the surface of commercially pure titanium (Cp-Ti) was covered by a 21–95 µm-thick aluminum oxide layer using plasma electrolytic oxidation. Coating characterization revealed the formation of nodular and granular α- and γ-Al2O3 phases with minor amounts of TiAl2O5 and Na2Ti4O9 which yielded a maximum 49.0 GPa hardness and 50 N adhesive critical load. The corrosion resistance behavior in 3.5 wt.% NaCl solution of all plasma electrolytic oxidation (PEO) coatings was found to be two orders of magnitude higher compared to bare Ti substrate.

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Bioactive Coatings Formed on Titanium by Plasma Electrolytic Oxidation: Composition and Properties

Materials ◽

10.3390/ma13184121 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4121 ◽

Cited By ~ 3

Author(s):

Dmitry V. Mashtalyar ◽

Konstantine V. Nadaraia ◽

Andrey S. Gnedenkov ◽

Igor M. Imshinetskiy ◽

Mariia A. Piatkova ◽

...

Keyword(s):

Plasma Electrolytic Oxidation ◽

Electrochemical Impedance ◽

Pure Titanium ◽

Corrosion Current ◽

Bare Metal ◽

Commercially Pure Titanium ◽

Bioactive Coatings ◽

Commercially Pure ◽

Electrolytic Oxidation ◽

Plasma Electrolytic

Bioactive coatings on VT1-0 commercially pure titanium were formed by the plasma electrolytic oxidation (PEO). A study of the morphological features of coatings was carried out using scanning electron microscopy. A composition of formed coatings was investigated using energy-dispersive spectroscopy and X-ray diffractometry analysis. It was shown that PEO-coatings have calcium phosphate in their composition, which increases the bioactivity of the surface layer. Electrochemical properties of the samples were studied by potentiondynamic polarization and electrochemical impedance spectroscopy in different physiological media: simulated body fluid and minimum essential medium. The data of electrochemical studies indicate more than 15 times decrease in the corrosion current density for the sample with coating (5.0 × 10−9 A/cm2) as compared to the bare titanium (7.7 × 10−8 A/cm2). The formed PEO-layers have elastoplastic properties close to human bone (12–30 GPa) and a lower friction coefficient in comparison with bare metal. The wettability of PEO-layers increased. The contact angle for formed coatings reduced by more than 60° in comparison with bare metal (from 73° for titanium to 8° for PEO-coating). Such an increase in surface hydrophilicity contributes to the greater biocompatibility of the formed coating in comparison with commercially pure titanium. PEO can be prospective as a method for improving titanium surface bioactivity.

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SEM and EDS Characterization of Porous Coatings Obtained On Titaniumby Plasma Electrolytic Oxidation in Electrolyte Containing Concentrated Phosphoric Acid with Zinc Nitrate

Advances in Materials Science ◽

10.1515/adms-2017-0010 ◽

2017 ◽

Vol 17 (2) ◽

pp. 41-54 ◽

Cited By ~ 6

Author(s):

K. Rokosz ◽

T. Hryniewicz ◽

K. Pietrzak ◽

W. Malorny

Keyword(s):

Phosphoric Acid ◽

Plasma Electrolytic Oxidation ◽

Pure Titanium ◽

Zinc Nitrate ◽

Porous Coatings ◽

Electrolytic Oxidation ◽

Micro Arc Oxidation ◽

Plasma Electrolytic ◽

Peo Coatings

AbstractThe SEM and EDS results of porous coatings formed on pure titanium by Plasma Electrolytic Oxidation (Micro Arc Oxidation) under DC regime of voltage in the electrolytes containing of 500 g zinc nitrate Zn(NO3)2·6H2O in 1000 mL of concentrated phosphoric acid H3PO4at three voltages, i.e. 450 V, 550 V, 650 V for 3 minutes, are presented. The PEO coatings with pores, which have different shapes and the diameters, consist mainly of phosphorus, titanium and zinc. The maximum of zinc-to-phosphorus (Zn/P) ratio was found for treatment at 650 V and it equals 0.43 (wt%) | 0.20 (at%), while the minimum of that coefficient was recorded for the voltage of 450 V and equaling 0.26 (wt%) | 0.12 (at%). Performed studies have shown a possible way to form the porous coatings enriched with zinc by Plasma Electrolytic Oxidation in electrolyte containing concentrated phosphoric acid H3PO4with zinc nitrate Zn(NO3)2·6H2O.

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Effects of a Carbon Nanotube Additive on the Corrosion-Resistance and Heat-Dissipation Properties of Plasma Electrolytic Oxidation on AZ31 Magnesium Alloy

Materials ◽

10.3390/ma11122438 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2438 ◽

Cited By ~ 4

Author(s):

Myungwon Hwang ◽

Wonsub Chung

Keyword(s):

Corrosion Resistance ◽

Carbon Nanotube ◽

Plasma Electrolytic Oxidation ◽

Heat Dissipation ◽

X Ray ◽

Steady State Method ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Dissipation Property ◽

Peo Coatings

Plasma electrolytic oxidation (PEO) coating was obtained on AZ31 Mg alloy using a direct current in a sodium silicate-based electrolyte with and without a carbon nanotube (CNT) additive. The surface morphology and phase composition of the PEO coatings were investigated through field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The corrosion-resistance properties of the PEO coatings were evaluated using potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. Furthermore, the heat-dissipation property was evaluated by a heat-flux measurement setup using a modified steady-state method and Fourier transform infrared spectroscopy (FT-IR). The results demonstrate that, by increasing the concentration of CNT additive in the electrolyte, the micropores and cracks of the PEO coatings are greatly decreased. In addition, the anticorrosion performance of the PEO coatings that incorporated CNT for the protection of the Mg substrate was improved. Finally, the coating’s heat-dissipation property was improved by the incorporation of CNT with high thermal conductivity and high thermal emissivity.

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Formation of PEO-Coatings for Implants Materials

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.312.309 ◽

2020 ◽

Vol 312 ◽

pp. 309-313

Author(s):

Konstantine V. Nadaraia ◽

Arina I. Pleshkova ◽

Mariia A. Piatkova ◽

Igor M. Imshinetsky ◽

Dmitry V. Mashtalyar ◽

...

Keyword(s):

Bone Mineralization ◽

Pure Titanium ◽

Commercially Pure Titanium ◽

Cellular Processes ◽

Commercially Pure ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Peo Coatings ◽

Uncoated Titanium ◽

Biocompatible Coatings

The paper presents results of investigation of biocompatible coatings on VT1-0 commercially pure titanium formed using plasma electrolytic oxidation (PEO) method. The effects of samples with different surface treatment on the functional activity of cells innate immunity have been studied. The study of enzymes has showed the higher stimulation of cellular metabolism during the first hour of contact with the PEO-coating in comparison with the uncoated titanium. The smallest immunostimulatory influence has been obtained for PEO-coating. It has been established that PEO-layers on titanium affect the functional state of cellular processes accompanying bone mineralization.

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MICROSTRUCTURE AND WEARING PROPERTIES OF PEO COATINGS: EFFECTS OF Al2O3 AND TiO2

Surface Review and Letters ◽

10.1142/s0218625x18501020 ◽

2018 ◽

Vol 25 (05) ◽

pp. 1850102 ◽

Cited By ~ 2

Author(s):

Y. ZHANG ◽

W. FAN ◽

H. Q. DU ◽

Y. W. ZHAO

Keyword(s):

Photoelectron Spectroscopy ◽

Plasma Electrolytic Oxidation ◽

Xps Analysis ◽

X Ray Diffraction ◽

Properties Of Coatings ◽

X Ray ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Peo Coatings ◽

Scanning Electron

Plasma electrolytic oxidation (PEO) coatings were formed on aluminium alloy in additive Al2O3- and TiO2-containing Na2SiO3-based electrolytes, respectively. The effect of these additives on morphology, composition and wearing properties of coatings was investigated. The morphology and composition of coatings were studied by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Analysis of wearing properties of coatings were done by friction and wearing experiment. It was found that the use of additives greatly affects the surface morphology of coatings. It is shown that the content of [Formula: see text]-Al2O3 in coatings formed in Al2O3-containing electrolytes increased with the addition of Al2O3. However, the content of [Formula: see text]-Al2O3 in coatings formed in TiO2-containing electrolytes first increased and then decreased. Among these coatings, the coating formed in silicate-based electrolytes system containing 7[Formula: see text]g/L Al2O3 showed the most superior wearing properties.

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Characterization of Anatase Coatings on NiTi Shape Memory Alloy by Plasma Electrolytic Oxidation Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.121-126.3837 ◽

2011 ◽

Vol 121-126 ◽

pp. 3837-3841

Author(s):

Li Hong Lu ◽

Jing Wu Zhang ◽

De Jiu Shen

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Plasma Electrolytic Oxidation ◽

Niti Shape Memory Alloy ◽

Aqua Regia ◽

X Ray ◽

Niti Sma ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Peo Coatings

The anatase coatings was obtained by aqua regia dealloying and plasma electrolytic oxidation (PEO) method on NiTi shape memory alloy (SMA) substrate. The PEO manufacturability of NiTi SMA before and after dealloying was researched. The PEO surface morphologies of the aqua regia treated and untreated specimens were investigated with scanning electron microscopy (SEM). The composition of the PEO coatings was investigated with X-ray diffraction (XRD). The element concentration of the surface of the PEO-treated NiTi SMA was measured by an energy dispersive X-ray spectrometer (EDS). The results indicate that the pre-treatment technology by aqua regia dealloying can greatly improve the PEO manufacturability and the PEO morphologies of the NiTi SMA. The optimum dealloying parameters are at room temperature for 10 min. At this circumstance, the PEO manufacturability of the treated samples is most close to that of the industrial pure titanium. There are many honeycomb-like micro-pores in the surface of the PEO coatings, which act as discharging channels. The cracks are invisible in the SEM images of the PEO coatings. The PEO coatings formed on the NiTi is composed of Ti, Ni, Al, O, Au and P. The composition of the PEO coatings is mainly composed of NiTi phase and anatase phase.

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Formation and Properties of Oxide Coatings with Immobilized Zeolites Obtained by Plasma Electrolytic Oxidation of Aluminum

Metals ◽

10.3390/met11081241 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1241

Author(s):

Kristina Mojsilović ◽

Uroš Lačnjevac ◽

Srna Stojanović ◽

Ljiljana Damjanović-Vasilić ◽

Stevan Stojadinović ◽

...

Keyword(s):

Plasma Electrolytic Oxidation ◽

Processing Time ◽

Water Solution ◽

Activity Levels ◽

Oxide Coatings ◽

X Ray ◽

Electrolytic Oxidation ◽

Chemical And Phase Compositions ◽

Plasma Electrolytic ◽

Peo Coatings

In this paper, we employed plasma electrolytic oxidation (PEO) of aluminum in a water solution of sodium tungstate (Na2WO4∙2H2O) with the addition of the pure and Ce-loaded zeolites clinoptilolite and 13 X for the preparation of oxide coatings. The obtained coatings were characterized with respect to their morphologies and chemical and phase compositions using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and X-ray diffraction. The prepared coatings contained γ-alumina, WO3, and metallic tungsten. The surface morphologies of the obtained coatings strongly depended on the PEO processing time; the roughness of all coatings increased with PEO time, while porosity decreased with PEO processing time as a result of microdischarge coalescence and growth. All coatings contained elements originating from the substrate and from the electrolytes. Coatings containing zeolites with Ce showed higher photoactivity than those with immobilized pure zeolites. The highest photocatalytic activity levels were observed for coatings containing immobilized Ce-exchanged clinoptilolite processed for 10 min. It was observed that both clinoptilolite and 13X zeolites improved the features of the PEO coatings in a similar manner, making natural and abundant clinoptilolite an excellent candidate for various applications.

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Titanium carbide’s effects on coatings formed on D16T aluminum alloy by plasma electrolytic oxidation

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-06-2019-2149 ◽

2020 ◽

Vol 67 (1) ◽

pp. 48-58

Author(s):

Wanying Liu ◽

Junjie Yang ◽

Yuhong Qiu ◽

Ying Liu ◽

Kuanhai Deng

Keyword(s):

Corrosion Resistance ◽

Aluminum Alloy ◽

Titanium Carbide ◽

Plasma Electrolytic Oxidation ◽

Ceramic Coatings ◽

Content Type ◽

X Ray ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Peo Coatings

Purpose The preferable concentration of titanium carbide was optimized and added as an additive to the micro-arc oxidation electrolyte to produce a high corrosion-resistant coating on D16T aluminum alloy. Design/methodology/approach Ceramic coatings were deposited on D16T aluminum alloy by plasma electrolytic oxidation in alkaline silicate electrolytes with micron titanium carbide particle suspending at different concentrations. Influences of additive concentration on morphology, elemental and phase composition and corrosion resistance of doped PEO coatings were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical methods, respectively. Findings Results revealed that suspending titanium carbide additives incorporated into ceramic coatings through discharging channels and chemically transformed into amorphous stage. The content of titanium in the doped coatings increased with the increasing concentration of suspending micron additive. Compared with the coating without particle addition, the corrosion resistance of the coating produced in 8 g/L titanium carbide suspension increased more than 20 times. The result indicated that the incorporation of titanium into the PEO coatings formed on the D16T aluminum alloy could effectively improve the corrosion resistance. Originality/value The mechanism of corporation of TiC and the mechanism of improving the corrosion resistance of the coating were proposed.

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Influence of Different Electrolyte Additives and Structural Characteristics of Plasma Electrolytic Oxidation Coatings on AZ31 Magnesium Alloy

Coatings ◽

10.3390/coatings10090817 ◽

2020 ◽

Vol 10 (9) ◽

pp. 817

Author(s):

Zhiquan Huang ◽

Ruiqiang Wang ◽

Xintong Liu ◽

Dongdong Wang ◽

Heng Zhang ◽

...

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Plasma Electrolytic Oxidation ◽

Electrochemical Impedance ◽

Ceramic Layer ◽

Az31 Magnesium Alloy ◽

Electrolyte Additives ◽

X Ray ◽

Electrolytic Oxidation ◽

Plasma Electrolytic

Coatings prepared by different electrolyte additives were investigated on AZ31 magnesium alloy by plasma electrolytic oxidation. In this study, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis were employed to assess the morphologies, chemical and phase compositions of the plasma electrolytic oxidation (PEO) coatings, respectively. Furthermore, electrochemical impedance spectroscopy was used to evaluate the corrosion behavior of the composite coating. The investigation of the effect of electrolyte additives in the base electrolyte showed that the PEO specimens exhibit different surface and cross-sectional morphologies, and phase compositions. The results showed that SiO32− was conducive to the growth of the ceramic layer, and the ceramic layer developing in the electrolyte which contained AlO2− showed a typical double-layer structure. The corrosion resistance of coating formed in a phosphate bath was higher than that of the coating formed in silicate bath and coating formed in an aluminate bath. Moreover, the corrosion resistance of the coating formed in the fluoride bath was the highest.

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