Systematic optimization of corrosion, bioactivity, and biocompatibility behaviors of calcium-phosphate plasma electrolytic oxidation (PEO) coatings on titanium substrates

Author(s):  
Maryam Molaei ◽  
Arash Fattah-alhosseini ◽  
Meisam Nouri ◽  
Alireza Nourian
Author(s):  
Tatiana S. Zaporozhets ◽  
Tatiana P. Smolina ◽  
Anna K. Gazha ◽  
Artyom V. Puz ◽  
Sergeiy. L. Sinebryukhov ◽  
...  

Current strategies for developing the biomaterials suggest passive modulation of osteoinductive and osteoconductive properties of the implant surface through a change in their physical and chemical parameters. Also, the osseointegration of implant depends on the reaction of the immune system, the severity of which is determined by physical and chemical properties of the material and the morphological features of the coating. In this paper, the plasma electrolytic oxidation (PEO) method for the formation of biologically active compositional corrosion resistant calcium phosphate coatings on titanium BT1-0 and magnesium alloy MA8, designed for bone bioengineering was used. Bioactive PEO coatings were additionally treated with superdispersed polytetrafluoroethylene (SPTFE) in order to improve anti-corrosion properties. The cellular and molecular aspects of immunological compatibility of bioactive calcium phosphate coatings formed on titanium and magnesium alloys by promising technology of plasma electrolytic oxidation and intended for bone tissue bioengineering were studied. It is shown that PEO coatings formed on titanium and magnesium induce an activation of human peripheral blood leukocytes in vitro, associated with increased expression of activation of molecules of CD69, CD38, CD11b on the cell membranes while shedding L-selectin (CD62L). Influence of coating process technologies on the intensity of the activation processes was established. Contact cells with calcium-phosphate PEO coatings formed on titanium and magnesium alloys induced a less pronounced activation in comparison with the untreated implants. The minimal reaction of the cells of the innate immunity was observed at using a composite of PEO coatings with SPTFE, obtained by electrophoretic deposition. The composite coating on magnesium alloys induces response of the cells of the innate immunity, comparable with the response to the coatings on titanium alloys. On the whole, immunological characteristics of the PEO coatings on titanium BT1-0 and magnesium alloy of MA8 demonstrate possibility of development of materials and wares for implant surgery, including bioresorbable alloys on magnesium base. For citation:Zaporozhets T.S., Puz A.V., Sinebryukhov S.L., Gnedenkov S.V., Smolina T.P., Gazha A.K. Comparative analysis of immunological compatibility of bioactive calcium phosphate coatings on titanium and magnesium alloys. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 2. P. 45-51.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1375
Author(s):  
Soumya Sikdar ◽  
Pramod V. Menezes ◽  
Raven Maccione ◽  
Timo Jacob ◽  
Pradeep L. Menezes

Plasma electrolytic oxidation (PEO) is a novel surface treatment process to produce thick, dense metal oxide coatings, especially on light metals, primarily to improve their wear and corrosion resistance. The coating manufactured from the PEO process is relatively superior to normal anodic oxidation. It is widely employed in the fields of mechanical, petrochemical, and biomedical industries, to name a few. Several investigations have been carried out to study the coating performance developed through the PEO process in the past. This review attempts to summarize and explain some of the fundamental aspects of the PEO process, mechanism of coating formation, the processing conditions that impact the process, the main characteristics of the process, the microstructures evolved in the coating, the mechanical and tribological properties of the coating, and the influence of environmental conditions on the coating process. Recently, the PEO process has also been employed to produce nanocomposite coatings by incorporating nanoparticles in the electrolyte. This review also narrates some of the recent developments in the field of nanocomposite coatings with examples and their applications. Additionally, some of the applications of the PEO coatings have been demonstrated. Moreover, the significance of the PEO process, its current trends, and its scope of future work are highlighted.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 401
Author(s):  
Ruzil Farrakhov ◽  
Olga Melnichuk ◽  
Evgeny Parfenov ◽  
Veta Mukaeva ◽  
Arseniy Raab ◽  
...  

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.


2017 ◽  
Vol 17 (2) ◽  
pp. 41-54 ◽  
Author(s):  
K. Rokosz ◽  
T. Hryniewicz ◽  
K. Pietrzak ◽  
W. Malorny

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.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2438 ◽  
Author(s):  
Myungwon Hwang ◽  
Wonsub Chung

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.


Author(s):  
Alex Lugovskoy ◽  
Lyubov Snizhko

In this review, the main kinetics and mechanism regularities of plasma electrolytic oxidation (PEO) of aluminum alloys are discussed. The material and heat balances of the PEO process, including anomalous gas evolution and possible thermochemical reactions are presented for the first time. Side effects accompanying spark discharges from both the surface and the electrolyte sides are analyzed. The influences of electrical regime (direct, alternative, and pulse current) on the rate of coatings growth are summarized from the electrochemical point of view. Different modes of anodic polarization and electrolyte composition (alkaline solutions with inorganic polymers and dispersed constituents) are discussed in the applicative aspect.


2018 ◽  
Vol 386 ◽  
pp. 321-325
Author(s):  
Igor M. Imshinetsky ◽  
Sergey V. Gnedenkov ◽  
Sergey L. Sinebryukhov ◽  
Dmitry V. Mashtalyar ◽  
Andrew V. Samokhin ◽  
...  

The way of protective coatings formation on MA8 magnesium alloy by plasma electrolytic oxidation (PEO) in the electrolyte containing composite zirconia-silica nanoparticles has been developed. It is shown that the coatings, which contain nanoparticles, have a significant advantage in comparison with the surface layers obtained without their use.


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