Titania coating formation on hydrostatically extruded pure titanium by micro-arc oxidation method

2021 ◽  
Author(s):  
Ł. Maj ◽  
D. Wojtas ◽  
A. Jarzębska ◽  
M. Bieda ◽  
K. Trembecka-Wójciga ◽  
...  
Keyword(s):  
Pure Titanium ◽  
Oxidation Method ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Titania Coating

scholarly journals Biocoatings synthesized on magnesium alloy in system Ca3(PO4)2–CaSiO3 by micro-arc oxidation method

2021 ◽  
Vol 1954 (1) ◽  
pp. 012037
Author(s):  
M B Sedelnikova ◽  
A V Ugodchikova ◽  
T V Tolkacheva ◽  
Yu P Sharkeev ◽  
O V Kazmina ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Oxidation Method ◽  
Micro Arc Oxidation

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

2017 ◽  
Vol 17 (2) ◽  
pp. 41-54 ◽  
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.

Preparation and properties of hydroxyapatite-containing titania coating by micro-arc oxidation

2006 ◽  
Vol 60 (20) ◽  
pp. 2538-2543 ◽  
Author(s):  
Jian-zhi Chen ◽  
Yu-long Shi ◽  
Lei Wang ◽  
Feng-ying Yan ◽  
Fu-qiang Zhang
Keyword(s):  
Micro Arc Oxidation ◽  
Titania Coating

Corrosion and Wear Protection through Micro Arc Oxidation Coatings in Aluminum and Its Alloys

2019 ◽  
Author(s):  
L. Rama Krishna ◽  
G. Sundararajan
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
High Hardness ◽  
Basic Mechanism ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Wear And Corrosion Resistance ◽  
Technological Limitations

This article presents the brief overview of fairly recent and eco-friendly micro arc oxidation (MAO) coating technology. The weight-cost-performance benefits in general raised the interest to utilize lightweight materials, especially the aluminum and its alloys. Despite numerous engineering advantages, the aluminum alloys themselves do not possess suitable tribology and corrosion resistance. Therefore, improvements in surface properties are essential to enable developing potential industrial applications. For improving wear and corrosion resistance of Al alloys, the most demanding surface properties are high hardness and chemical inertness. The technical and technological limitations associated with traditional anodizing and hard anodizing processes have been the strongest driving force behind the development of new MAO technology. While presenting the key technological elements associated with the MAO process, the basic mechanism of coating formation and its phase gradient nature is presented. Influence of various process parameters including the electrolyte composition has been discussed. The typical microstructural features and distribution of α- and γ-Al2O3 phases across the coating thickness as a key strategy to form dense coatings with required mechanical, tribological, and corrosion properties which are vital to meet potential application demands are briefly illustrated.

scholarly journals Phase composition of coatings on the D16 alloy during micro-arc oxdation in alkaline and silicate electrolytes

2020 ◽  
Vol 1,2020 (1,2020 (124)) ◽  
pp. 51-55
Author(s):  
Subbotina V ◽  
Belozerov V ◽  
Sobol’ O
Keyword(s):  
Phase Composition ◽  
Liquid Glass ◽  
Amorphous State ◽  
Practical Significance ◽  
Alkaline Electrolyte ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Al2o3 Phase ◽  
Α Al2o3

Goal. The influence of electrolysis conditions at different electrolyte compositions on the phase formation of coatings obtained by micro-arc oxidation (MDO) on an aluminum alloy D16 was studied. Method. For electrolysis, two types of electrolytes were used: alkaline electrolyte (solution (KOH) in distilled water), silicate electrolyte (with different percentages of Na2SiO3 component). Research results. It was found that the phase composition of the MAO coatings obtained in an alkaline (KOH) electrolyte mainly consists of γ - Al2O3 phases and, to a much lesser extent, the α-Al2O3 phases. An increase in the KOH concentration leads to a shift in the γ – Al2O3 → α – Al2O3 polymorphic reaction toward the formation of the hardest α-Al2O3 phase (corundum). The formation of the preferred orientation of the growth of crystallites of γ – Al2O3 and α – Al2O3 phases during their formation in an alkaline electrolyte was not detected. Scientific novelty. A significant influence on the mechanism and processes of coating formation is made by the addition of liquid glass (Na2SiO3) in the electrolyte. In this case, the growth rate of the coating increases significantly, but the size of the ordering regions decreases from crystalline to X-ray amorphous. The phase composition of the MAO coatings, when they are formed in a silicate electrolyte, varies from a mixture of the γ - Al2O3 phase and mullite (3Al2O3 • 2SiO2) with a low content of liquid glass (10 g/l Na2SiO3) to the formation of only the X-ray amorphous phase with a high content of liquid glass in the electrolyte (50 g/l Na2SiO3). Practical significance. It was concluded that the use of an alkaline or silicate electrolyte with different percentages allows a wide variation of both the phase composition and structural state (α- Al2O3 and γ- Al2O3 phases, mullite (3Al2O3 • 2SiO2) or X-ray amorphous state) and the kinetics of growth the coating itself.

scholarly journals Novel Mg-Incorporated Micro-Arc Oxidation Coatings for Orthopedic Implants Application

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5710
Author(s):  
Rongfa Zhang ◽  
Sheng Zhong ◽  
Lilan Zeng ◽  
Hongyu Li ◽  
Rongfang Zhao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Potassium Hydroxide ◽  
Surface Characterization ◽  
Orthopedic Implants ◽  
Collagen Secretion ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Orthopedic Applications ◽  
Mg Content ◽  
Micropore Size

In this study, Ti-6Al-4V alloy samples were processed by micro-arc oxidation (MAO) in phytic acid (H12Phy) electrolytes with the addition of different concentrations of EDTA-MgNa2 (Na2MgY) and potassium hydroxide (KOH). The surface characterization and cytocompatibility of MAO-treated samples were evaluated systematically. H12Phy is a necessary agent for MAO coating formation, and the addition of Na2MgY and KOH into the electrolytes increases the surface roughness, micropore size and Mg contents in the coatings. The MAO coatings are primarily composed of anatase, rutile, MgO and Mg3(PO4)2. Magnesium (Mg) ions in the electrolytes enter into MAO coatings by diffusion and electromigration. The MAO coatings containing 2.97 at% Mg show excellent cell viability, adhesion, proliferation, alkaline phosphatase activity, extracellular matrix (ECM) mineralization and collagen secretion, but the cytocompatibility of the MAO coatings containing 6.82 at% Mg was the worst due to the excessively high Mg content. Our results revealed that MAO coatings with proper Mg contents improve the cytocompatibility of the Ti-6Al-4V alloys and have large potential in orthopedic applications.

Effect of Zn content on cytoactivity and bacteriostasis of micro-arc oxidation coatings on pure titanium

2013 ◽  
Vol 228 ◽  
pp. S428-S432 ◽  
Author(s):  
B.H. Zhao ◽  
W. Zhang ◽  
D.N. Wang ◽  
W. Feng ◽  
Y. Liu ◽  
...  
Keyword(s):  
Pure Titanium ◽  
Zn Content ◽  
Micro Arc Oxidation

scholarly journals Tribological functionalization of titanium alloys by Micro-Arc Oxidation for marine applications

2020 ◽  
Vol 321 ◽  
pp. 09001
Author(s):  
Aude MATHIS ◽  
Thierry MILLOT ◽  
Vincent BRANGER ◽  
Remy MULLER ◽  
Jean-Yves GUENEHEUX
Keyword(s):  
Friction Coefficient ◽  
Titanium Alloys ◽  
Pure Titanium ◽  
Dynamic Contact ◽  
Electrochemical Process ◽  
Commercially Pure Titanium ◽  
Tribological Behaviour ◽  
Stick Slip ◽  
Micro Arc Oxidation ◽  
Slip Phenomenon

Micro-arc Oxidation (MAO) process is a plasma assisted electrochemical process, which allows formation of ceramic-like dry oxides on top of light alloys surfaces. The good corrosion resistance as well as the low density of titanium alloys are recognized and so required for conception of structural parts in marine environment. However, their tribological behaviour reveals an important tendency to stick-slip phenomenon, which makes use of these alloys for dynamic contact mechanisms difficult. Through the MAO project from IRT M2P, formation of a MAO coating composed of aluminium titanate has been investigated to improve tribological behaviour of a commercially pure titanium (Grade 2) and an α+β alloy (TA6V, Grade 5). Pin-on-disc testing has been carried out to evaluate friction coefficient and the presence or not of stick-slip phenomenon in various contact configurations (involving non-treated titanium surfaces, MAO treated surfaces, with steel or titanium balls …) in dry or artificial seawater media. Those test campaigns are completed by evaluation of fatigue behaviour, and tribological testing on a demonstrator. Finally, this study highlights influence of MAO coating on diminishing (to removed) stick-slip phenomenon, accompanied by a reduction of friction coefficient, whatever the kind of contact (single treated surface or both ones) and the medium.

scholarly journals Zn- or Cu-Containing CaP-Based Coatings Formed by Micro-arc Oxidation on Titanium and Ti-40Nb Alloy: Part I—Microstructure, Composition and Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4116 ◽  
Author(s):  
Ekaterina G. Komarova ◽  
Yurii P. Sharkeev ◽  
Mariya B. Sedelnikova ◽  
Konstantin A. Prosolov ◽  
Igor A. Khlusov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Adhesive Strength ◽  
Applied Voltage ◽  
Oxidation Process ◽  
Pure Titanium ◽  
Atomic Ratio ◽  
Linear Increase ◽  
Microcrystalline Structure ◽  
Micro Arc Oxidation ◽  
Alloy Part

Zn- and Cu-containing CaP-based coatings, obtained by micro-arc oxidation process, were deposited on substrates made of pure titanium (Ti) and novel Ti-40Nb alloy. The microstructure, phase, and elemental composition, as well as physicochemical and mechanical properties, were examined for unmodified CaP and Zn- or Cu-containing CaP coatings, in relation to the applied voltage that was varied in the range from 200 to 350 V. The unmodified CaP coatings on both types of substrates had mainly an amorphous microstructure with a minimal content of the CaHPO4 phase for all applied voltages. The CaP coatings modified with Zn or Cu had a range from amorphous to nano- and microcrystalline structure that contained micro-sized CaHPO4 and Ca(H2PO4)2·H2O phases, as well as nano-sized β-Ca2P2O7, CaHPO4, TiO2, and Nb2O5 phases. The crystallinity of the formed coatings increased in the following order: CaP/TiNb < Zn-CaP/TiNb < Cu-CaP/TiNb < CaP/Ti < Zn-CaP/Ti < Cu-CaP/Ti. The increase in the applied voltage led to a linear increase in thickness, roughness, and porosity of all types of coatings, unlike adhesive strength that was inversely proportional to an increase in the applied voltage. The increase in the applied voltage did not affect the Zn or Cu concentration (~0.4 at%), but led to an increase in the Ca/P atomic ratio from 0.3 to 0.7.

scholarly journals Morphology and Wear Resistance of Composite Coatings Formed on a TA2 Substrate Using Hot-Dip Aluminising and Micro-Arc Oxidation Technologies

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 799 ◽  
Author(s):  
Shaopeng Wang ◽  
Lian Zhou ◽  
Changjiu Li ◽  
Zhengxian Li ◽  
Hongzhan Li
Keyword(s):  
Wear Resistance ◽  
Surface Composition ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Ceramic Coatings ◽  
Oxide Ceramic ◽  
Pure Aluminium ◽  
X Ray ◽  
Micro Arc Oxidation

Aluminium layers were coated onto the surface of pure titanium using hot-dip aluminising technology, and then the aluminium layers were in situ oxidised to form oxide ceramic coatings, using the micro-arc oxidation (MAO) technique. The microstructure and composition distribution of the hot-dip aluminium coatings and ceramic layers were studied by using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The phase structure of the MAO layers was studied using X-ray diffraction. The surface composition of the MAO layer was studied by X-ray photoelectron spectroscopy. The wear resistance of the pure titanium substrate and the ceramic layers coated on its surface were evaluated by using the ball-on-disc wear method. Therefore, aluminising coatings, which consist of a diffusion layer and a pure aluminium layer, could be formed on pure titanium substrates using the hot-dip aluminising method. The MAO method enabled the in-situ oxidation of hot-dip pure aluminium layers, which subsequently led to the formation of ceramic layers. Moreover, the wear resistance values of the ceramic layers were significantly higher than that of the pure titanium substrate.

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