scholarly journals Electrochemical evaluation of the hydroxyapatite coating synthesized on the AZ91 by electrophoretic deposition route

2021 ◽  
Vol 1 (2) ◽  
pp. 85-91
Author(s):  
Arezoo Jangjoo Tazeh Kand ◽  
Fereshteh Afaghi ◽  
Arvin Taghizadeh Tabrizi ◽  
Hossein Aghajani ◽  
Hilal Demir Kivrak

The hydroxyapatite layer was deposited on the commercial magnesium alloy of AZ91 by electrophoretic deposition route, and the corrosion behavior of applied layers was studied by polarization and electrochemical impedance spectroscopy at the Simulated Body Fluid (SBF) solution. The best corrosion resistance improvement was obtained for the sample synthesized at 40 V within 4 minutes. Also, the morphology of coated samples was studied by atomic force microscopy (AFM) and the surface parameters were measured. It could be concluded that the calculated values for surface parameters including surface roughness, maximum peak height, maximum pit depth, and maximum peak have a meaningful relationship with corrosion resistance.

2011 ◽  
Vol 356-360 ◽  
pp. 2707-2710 ◽  
Author(s):  
Hong Yun ◽  
Chang Jian Lin ◽  
Qun Jie Xu

Anatase of TiO2films were supplied on the surface of 316L stainless steel by a sol–gel process followed by hydrothermal treatment in water. The as-prepared samples were characterized with filed emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Raman spectroscopy. The corrosion performances of the films in 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and polarization measurements. The results revealed that the corrosion resistance of the TiO2films via the hydrothermal treatment at 170°C for 4h exceeded that of the counterparts treated by conventional calcination at 450°C. This could be attributed that the surface of such a sample was more compact and uniform, relatively well-crystallized, able to act as an optimal barrier layer to metallic substrates.


2018 ◽  
Vol 778 ◽  
pp. 111-117 ◽  
Author(s):  
Zaeem Ur Rehman ◽  
Mohsin Ali Raza ◽  
Faizan Ali Ghauri ◽  
Rumasa Kanwal ◽  
Akhlaq Ahmad ◽  
...  

In this study graphene coatings were deposited on mild steel substrate using feasible and environmental friendly method. The successful synthesis of graphite oxide was carried by the modified Hummer’s method. Graphene oxide (GO) coatings were developed from GO/water suspension using electrophoretic deposition (EPD). The EPD parameters voltage and deposition time were varied to deposit uniform adherent coatings. The coatings were post heat treated at 200 °C in vacuum for 4h to assess the effect on coated samples. GO and GO-EPD coating morphology were characterized using Fourier transform infrared spectroscopy (FTIR), Atomic force microscopy (AFM) and Scanning electron microscopy (SEM). Linear polarization (LPR) and electrochemical impedance spectroscopy (EIS) tests were performed in saline solution to evaluate electrochemical response. Coatings were partially reduced due to removal of oxygen containing functional groups during EPD and post heat treatments. The GO post heat treated coating had better corrosion resistance ~2 times than that of bare mild steel and higher charge transfer resistance.


2018 ◽  
Vol 25 (08) ◽  
pp. 1950024
Author(s):  
M. ASLAN ◽  
O. ÇOMAKLI ◽  
M. YAZICI ◽  
A. F. YETIM ◽  
Ö. BAYRAK ◽  
...  

The present study was focussed on investigating the corrosion properties of plasma-oxidized and -nitrided CoCrMo alloys under different conditions. The structural properties of untreated and treated samples were examined by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Corrosion behavior of samples was mainly investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in simulated body fluid solution. The results showed that corrosion resistance of the oxidized layers was better than that of the nitrided ones. The corrosion resistance of the alloys increased as the plasma oxidation process temperature and time increased. However, the corrosion resistance of the alloys reduced with increase in the process temperature and time after plasma nitriding process.


2008 ◽  
Vol 591-593 ◽  
pp. 55-60 ◽  
Author(s):  
E.P. Banczek ◽  
S.L. de Assis ◽  
Marize Varella de Oliveira ◽  
Waléria Silva de Medeiros ◽  
Luiz Carlos Pereira ◽  
...  

In this work, porous titanium samples processed by powder metallurgy and coated with biomimetic coatings, obtained during different periods of immersion in a simulated body fluid (SBF), were tested for corrosion resistance in a phosphate buffer solution (PBS). Uncoated samples were also tested for comparison. The corrosion resistance of both types of titanium samples was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarisation curves. The electrochemical results indicated the formation of a surface film on the porous Ti samples with immersion in the SBF solution and this biomimetic film increased their corrosion resistance. This film helps osteointegration besides increasing corrosion resistance.


2016 ◽  
Vol 1139 ◽  
pp. 69-73
Author(s):  
Lidia Benea ◽  
Iulian Bounegru ◽  
Alexandru Chiriac

Novel hybrid Co/UHMWPE biocoatings were obtained by electrochemical deposition of cobalt from a cobalt sulfate plating bath with ultra high molecular weight polyethylene (UHMWPE - particle size of 10 μm) as dispersed particles in order to provide possible biomedical coatings applications. The surface morphology and topography, roughness and chemical composition were investigated, as a function of UHMWPE particles concentration in the plating bath by scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray analysis (EDX). Electrochemical corrosion resistance investigations were carried out in simulating body fluid solution (SBF), using electrochemical impedance spectroscopy (EIS) method at different exposure times. The results proved a good corrosion resistance of the obtained hybrid Co/UHMWPE coatings.


2021 ◽  
Vol 1 (2) ◽  
pp. 121-126
Author(s):  
Hossein Aghajani ◽  
Seyed Ali Naziri Mehrabani ◽  
Arvin Taghizadeh Tabrizi ◽  
Falih Hussein Saddam

In this paper, the synthesis of the copper matrix nanocomposite and the effect of adding TiB2 nanoparticles on the copper matrix was investigated. Three different amounts of TiB2 nanoparticles 5, 10, and 15 wt% were added and sintering was carried out at 900 oC for 4 hours under argon atmosphere. The phase formation of achieved nanocomposites was studied by X-ray diffractometer and the morphology of the synthesized samples was studied by field emission scanning electron microscopy and atomic force microscopy. The polarization and electrochemical impedance spectroscopy (EIS) at 3.5 wt% NaCl solution at room temperature was were carried out to evaluate the corrosion behavior of synthesized samples. Results show that adding the TiB2 nanoparticles decrease the corrosion resistance by the formation of galvanic couples, but the effect of amounts of porosities on the corrosion resistance is higher. It is revealed that the variation of the surface roughness is in direct relation to the value of polarization current density.


Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 89
Author(s):  
Wei Yuan ◽  
Qian Hu ◽  
Jiao Zhang ◽  
Feng Huang ◽  
Jing Liu

This study modified graphene oxide (GO) with hydrophilic octadecylamine (ODA) via covalent bonding to improve its dispersion in silicone-modified epoxy resin (SMER) coatings. The structural and physical properties of ODA-GO were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle tests. The ODA-GO composite materials were added to SMER coatings by physical mixing. FE-SEM, water absorption, and contact angle tests were used to evaluate the physical properties of the ODA-GO/SMER coatings, while salt spray, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe (SKP) methods were used to test the anticorrosive performance of ODA-GO/SMER composite coatings on Q235 steel substrates. It was found that ODA was successfully grafted onto the surfaces of GO. The resulting ODA-GO material exhibited good hydrophobicity and dispersion in SMER coatings. The anticorrosive properties of the ODA-GO/SMER coatings were significantly improved due to the increased interfacial adhesion between the nanosheets and SMER, lengthening of the corrosive solution diffusion path, and increased cathodic peeling resistance. The 1 wt.% ODA-GO/SMER coating provided the best corrosion resistance than SMER coatings with other amounts of ODA-GO (including no addition). After immersion in 3.5 wt.% NaCl solution for 28 days, the low-frequency end impedance value of the 1 wt.% ODA-GO/SMER coating remained high, at 6.2 × 108 Ω·cm2.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.


Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 704
Author(s):  
Marija Riđošić ◽  
Nebojša D. Nikolić ◽  
Asier Salicio-Paz ◽  
Eva García-Lecina ◽  
Ljiljana S. Živković ◽  
...  

Electrodeposition and characterization of novel ceria-doped Zn-Co composite coatings was the main goal of this research. Electrodeposited composite coatings were compared to pure Zn-Co coatings obtained under the same conditions. The effect of two ceria sources, powder and home-made sol, on the morphology and corrosion resistance of the composite coatings was determined. During the electrodeposition process the plating solution was successfully agitated in an ultrasound bath. The source of the particles was found to influence the stability and dispersity of plating solutions. The application of ceria sol resulted in an increase of the ceria content in the resulting coating and favored the refinement from cauliflower-like morphology (Zn-Co) to uniform and compact coral-like structure (Zn-Co-CeO2 sol). The corrosion resistance of the composite coatings was enhanced compared to bare Zn-Co as evidenced by electrochemical impedance spectroscopy and scanning Kelvin probe results. Zn-Co doped with ceria particles originating from ceria sol exhibited superior corrosion resistance compared to Zn-Co-CeO2 (powder) coatings. The self-healing rate of artificial defect was calculated based on measured Volta potential difference for which Zn-Co-CeO2 (sol) coatings exhibited a self-healing rate of 73.28% in a chloride-rich environment.


Sign in / Sign up

Export Citation Format

Share Document