The Effect of Oxidized Time to Structure and Composition of Micro-Arc Oxidization Ceramic Coating of Pure Titanium

2016 ◽  
Vol 852 ◽  
pp. 984-991
Author(s):  
Lin Xu ◽  
Jian Ning Ding ◽  
Zhen Huang ◽  
Ni Na Han ◽  
Xiao Jing Xu ◽  
...  
Keyword(s):  
Ceramic Coating ◽  
Pure Titanium ◽  
Relative Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Opposite Trend ◽  
Micro Arc Oxidation ◽  
Porous Oxide ◽  
3D Profilometer ◽  
Scanning Electron

The porous oxide TiO2 ceramic coating containing Ca and P is fabricated on the surface of pure titanium in the electrolyte of C4H6CaO4-NaH2PO4 by micro-arc oxidation (MAO) method. Scanning electron microscopy (SEM) and 3D profilometer are used to observe difference between morphology of coating surface under condition of different oxidized time. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) are used to discuss the effect of oxidized time to the ratio of Ca/P and phase composition of ceramic coating. Results indicate that the oxidized time has a little effect on structure and composition of MAO ceramic coating of pure titanium. After modified with MAO, pure titanium is rough and porous on its surface, its average aperture, porosity and roughness enlarge as oxidized time extends. The increase of oxidized time makes the ratio of Ca/P and the relative content of rutile TiO2 increases, but the relative content of anatase TiO2 shows opposite trend.

The Influences of Frequency on the Fabrication and Structural Studies of Micro-Arc Oxidization Ceramic Films Formed on Pure Titanium

2017 ◽  
Vol 727 ◽  
pp. 977-984
Author(s):  
Lin Xu ◽  
Cong Wu ◽  
Xiao Jing Xu ◽  
Bo Quan Li ◽  
Xiao Ya Niu ◽  
...  
Keyword(s):  
Mixed Crystal ◽  
Pure Titanium ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Film ◽  
Ceramic Films ◽  
Micro Arc Oxidation ◽  
Porous Oxide ◽  
3D Profilometer

The porous oxide TiO2 ceramic film containing Ca and P is fabricated on the surface of pure titanium in the electrolyte of C4H6CaO4-NaH2PO4 by micro-arc oxidation (MAO) method. The microscopic structure, elemental composition and phase components of Ceramic Film are studied with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), 3D profilometer and etc. Results indicate that the ceramic film on pure titanium by micro-arc oxidation is a porous mixed crystal structure which contains anatase TiO2 and rutile TiO2, and that the film is mainly composed of such elements as Ti, O, Ca and P. With frequency increasing, the number of micropores increases, the hole is decreased in diameter, porosity and roughness,and the surface is more smooth. The increase of frequencies makes the ratio of Ca/P decrease, the relative content of anatase TiO2 increase and rutile TiO2 decrease.

The Effect of Current Density to Surface Morphology and Component of Micro-Arc Oxidization Ceramic Coating of Pure Titanium

2016 ◽  
Vol 852 ◽  
pp. 992-999 ◽  
Author(s):  
Lin Xu ◽  
Jian Ning Ding ◽  
Zhen Huang ◽  
Ni Na Han ◽  
Xiao Jing Xu ◽  
...  
Keyword(s):  
Current Density ◽  
Mixed Crystal ◽  
Ceramic Coating ◽  
Pure Titanium ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Average Pore ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
3D Profilometer

The ceramic coating containing anatase TiO2 and rutile TiO2 is fabricated on the surface of pure titanium in the electrolyte of C4H6CaO4-NaH2PO4 by micro-arc oxidation (MAO) method. The effect of different current density to microscopic structure, elemental composition and phase components of Ceramic Coating are studied with scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), 3D profilometer and etc. Results indicate that the ceramic coating on pure titanium by micro-arc oxidation is a porous mixed crystal structure which is mainly composed of such elements as Ti, O, Ca and P. With current density increasing, the average pore diameter and roughness on film surface first increase and then decrease, the porosity increases, the ratio of Ca/P then decreases, the relative content of anatase TiO2 increases and that of rutile TiO2 decreases.

A Porous TiO2 Coating with Vermiform Morphology Formed on Ti through Micro-Arc Oxidation

2013 ◽  
Vol 652-654 ◽  
pp. 1818-1821
Author(s):  
Zhen Fei Liu ◽  
Wei Qiang Wang ◽  
Min Qi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Temperature ◽  
Rutile Phase ◽  
Sodium Tetraborate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Titania ◽  
Micro Arc Oxidation ◽  
Scanning Electron

A porous titania (TiO2) coating with vermiform slots was prepared on the Ti substrate through micro-arc oxidation (MAO) treatment using sodium tetraborate as electrolyte. Morphologies and phase structure were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Results show that the rutile phase increases and anatase decreases gradually with increasing MAO time. The electrolyte of sodium tetraborate has significant influence on the formation of vermiform coatings, which determine the corrosive patterning in the first stage during MAO processing. The evolution of vermiform morphology is proposed as followed: some corrosive pores appear on the surface before arcing; afterward, the adjacent micropores in the dense regions link each other due to the high temperature result from continuous arc action; then, the micropores grow up to big pits and combine with each other with increasing MAO treating time; finally, the vermiform morphology forms on the surface of Ti metal.

Ceramic Coatings of Magnesium Alloy for Biomaterial Applications

2010 ◽  
Vol 434-435 ◽  
pp. 634-637 ◽  
Author(s):  
Pu Liang Zhang ◽  
Bin Liu ◽  
Dong Zhang ◽  
Yong Wei Tao ◽  
Sheng Rong Yang ◽  
...  
Keyword(s):  
Body Fluid ◽  
Ceramic Coatings ◽  
Alkaline Treatment ◽  
Mg Alloy ◽  
X Ray Diffraction ◽  
Electrodeposition Technique ◽  
Corrosion Properties ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Porous Oxide

Ceramic coatings were produced on magnesium (Mg) alloy of AZ91D for biomaterial applications by micro-arc oxidation (MAO) and electrodeposition methods. The morphology, microstructure, phase composition and corrosion properties of the prepared coatings were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and potentiodynamic polarization tester, etc. The results indicated that a porous oxide layer was grown on the Mg alloy sheets after MAO process and the compositions of oxides were mainly Mg2SiO4 and MgO. After further electrodeposition and alkaline treatment, a flake-like structure diverging from centre to periphery was grown on the MAO coating and the coating was mainly made up of hydroxyapatite (HA). Moreover, the corrosion resistance of the Mg alloy after being treated with MAO and electrodeposition technique increases obviously, which was evaluated in stimulated body fluid (SBF).

Effects of graphene on the microstructure and properties of MAO coatings formed on AA7050

2020 ◽  
Vol 111 (6) ◽  
pp. 463-468
Author(s):  
Bo Xu ◽  
Yafeng He ◽  
Xiangzhi Wang ◽  
Weimin Gan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Composite Coatings ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Scanning Electron

Abstract Ceramic coatings were prepared on the surface of 7050 highstrength aluminum alloy using micro-arc oxidation in an aluminate electrolyte with added graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron, and electrochemical measurements were used, respectively. The addition of 9 g · L-1 of graphene to the electrolyte decreased the micro-pore size of the composite coatings and improved the density. In addition, with the addition of graphene, the roughness was the lowest, and the corrosion resistance was significantly improved.

Influences of Copper Complexes on the Properties of MAO Ceramic Coating on Titanium Alloy Surface

2014 ◽  
Vol 788 ◽  
pp. 138-143 ◽  
Author(s):  
Qiang Yao ◽  
Si Rong Yu ◽  
Hong Chao Chu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Titanium Alloy ◽  
Copper Complexes ◽  
Ceramic Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminium Titanate ◽  
Black Coating ◽  
Scanning Electron

The present work focuses on the influence of copper complexes in the MAO electrolyte on the structure and wears resistance of ceramic coating on the surface of titanium alloy. The coatings composition and the morphologies were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). It is shown that the working voltage of MAO reaction was lower after adding [Cu (NH3)4]2+than adding EDTA-Cu. The color of ceramic coating is black (prepared in the electrolyte with [Cu (NH3)4]2+) and brown (prepared in the electrolyte with EDTA-Cu). The black coating contained rutile TiO2, anatase TiO2and aluminium titanate (Al2TiO5), while the brown coating contained rutile and anatase only. The black coating which contained CuO compound was found to outperform brown coating in wear resistance.

MICROSTRUCTURE AND ELEMENT DISTRIBUTIONS OF CERAMIC-LIKE COATINGS ON THE AZ91 ALLOY BY MICRO-ARC OXIDATION

2006 ◽  
Vol 13 (01) ◽  
pp. 63-68 ◽  
Author(s):  
CHUANZHONG CHEN ◽  
QING DONG ◽  
DIANGANG WANG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Az91 Alloy ◽  
X Ray Diffraction ◽  
Surface Protection ◽  
X Ray ◽  
Porous Microstructure ◽  
Micro Arc Oxidation ◽  
Coating Matrix ◽  
Scanning Electron

Ceramic-like coatings were deposited on the substrate of the AZ91 alloy by micro-arc oxidation (MAO). Many methods like X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron diffraction spectroscopy (EDS) were used to analyze the structure and composition of the coating. XRD showed that the MAO coating was mainly composed of MgO . The results of SEM showed that the coating surface possessed a porous microstructure and the pore size was in the range of 1–3 μm. EDS indicated that the coating matrix was relatively dense and had a homogeneous thickness. The element silicon from the applied electrolyte could be absorbed into the coating in the MAO process. The hardness of the MgO coatings could reach 513 HV0.025 that was about four times higher than that of the substrate. It is expected that the coatings have a great potential in the surface protection of magnesium alloys.

Effects of Rare Earth (RE) Additives on Performances of Micro-Arc Oxidation Coatings Formed on Aluminum Alloy

2013 ◽  
Vol 850-851 ◽  
pp. 140-143 ◽  
Author(s):  
Dan Huang ◽  
Xiao Yan Zhang ◽  
De Feng Wu ◽  
Xiao Song Zhou
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Friction And Wear ◽  
Alloy Sample ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Cracks ◽  
Micro Arc Oxidation ◽  
Α Al2o3 ◽  
Scanning Electron

Scanning electron microscope (SEM), X-ray diffraction (XRD), VSP electrochemical workstation and friction and wear tester equipment are applied for comparing the effects on organizations and properties of micro-arc oxidation fabricated on a piece of aluminum alloy sample with additives of La (NO3)3 or Ce (SO4)2. The results revealed that both coatings with these two different additives are consisted of α-Al2O3 and γ-Al2O3, but the peaks of main phases are evident with La (NO3)3. Compared the two different coatings, it could be found that less micro-cracks can be observed from the coating with La (NO3)3 additive. Beside this, aperture in this coating is also smaller and corrosion resistance and wear resistance are much better.

Fabrication and Degradation Properties of Ca/P Contained Micro-Arc Oxidation Coating on Pure Magnesium

2020 ◽  
Vol 12 (5) ◽  
pp. 755-759 ◽  
Author(s):  
Ying-Xue Teng ◽  
Fang Liu ◽  
Cheng-Yang Li ◽  
Zhen Xu ◽  
Jing Guo
Keyword(s):  
Degradation Rate ◽  
Ceramic Coating ◽  
Medical Application ◽  
Pure Magnesium ◽  
X Ray Diffraction ◽  
Surface Protection ◽  
X Ray ◽  
Deposition Parameters ◽  
Micro Arc Oxidation ◽  
Degradation Properties

Nowadays, Mg based metals attract much attention because of their biodegradability and bioactivity. However, over fast degradation rate still restrict their widely medical application. Therefore, surface protection treatment is necessary to control the degradation rate. In this study, a ceramic coating was successfully fabricated on pure magnesium by Micro-arc oxidation (MAO) method. The surface quality was dramatically influenced by deposition parameters such as voltage and frequency. The composition of the sample was characterized by X-ray diffraction (XRD) and the surface morphology was characterized by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). The degradation behavior of MAO coated Mg was investigated. It is expected that pure Mg with MAO coating can be used for the orthopedic application especially as bone screw.

Spontaneous Crystallization Behavior of Phosphosilicate Glasses

2011 ◽  
Vol 183-185 ◽  
pp. 1626-1630
Author(s):  
Shu Jiang Liu ◽  
Yan Fei Zhang
Keyword(s):  
Alkaline Earth ◽  
Crystallization Behavior ◽  
Relative Content ◽  
The Other ◽  
Compositional Variation ◽  
X Ray Diffraction ◽  
Spontaneous Crystallization ◽  
X Ray ◽  
Degree Of Crystallization ◽  
Scanning Electron

We studied the spontaneous crystallization behavior for 60.5SiO2-2.5Al2O3-3P2O5- 18Na2O-16RMgO-16(1-R)CaO system glasses during cooling of melts through changing the relative content of alkaline-earth oxides. Such compositional variation leads to the formation of different crystalline phases, as well as different degree of crystallization, with the help of X-ray diffraction (XRD), heat capacity (Cp) and scanning electron microscopy (SEM). It is found that the obtained glasses are opalescent due to formation of orthorhombic NaCaPO4 during cooling when R≤0.5, and the degree of crystallization increases with substituting MgO for CaO. On the other hand, the spontaneous crystallized phases is hexagonal NaCaPO4 for R=0.75 and is Na2MgSiO4 for R=1.0, respectively, and besides, the appearance become transparent.

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