Study on Morphologies and Structures of Ceramic Coating Prepared by Micro-Arc Oxidation on TC4 Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 395-399 ◽  
Author(s):  
Chao Shi Qian ◽  
Peng Fei Li ◽  
Liang Liu ◽  
Feng Guo ◽  
Ya Ya
Keyword(s):  
Titanium Dioxide ◽  
Ceramic Coating ◽  
Atomic Ratio ◽  
Process Conditions ◽  
Mixture Ratio ◽  
Tc4 Titanium Alloy ◽  
Calcium Phosphorus ◽  
Tc4 Alloy ◽  
Micro Arc Oxidation ◽  
Modification Of Titanium

In this work, the effects of concentration and mixture ratio of Ca(CH3COO)2•H2O and Na5P3O10 in electrolyte on surface morphology, surface content and atomic ratio of calcium and phosphorus elements, and phase structure of ceramic coating prepared by micro-arc oxidation（MAO）on TC4 titanium alloy were studied, a suitable formula of electrolyte for bio-modification of titanium by MAO was obtained, Ca(CH3COO)2•H2O 20 g/L and Na5P3O10 9.3 g/L. Using this electrolyte with appropriate process conditions, the ceramic coating was prepared with porosity structure and combines well with the substrate. The pores distributed equably on the surface of ceramic coating and the size of the pores was in micron order. The surface of the ceramic coating contains calcium, phosphorus elements and their atom ratio is about 1.69 which nears to that of hydroxyapatite. The ceramic coating was composed of titanium dioxide in different crystal types which have been characterized by the X-ray diffraction (XRD). The anatase titanium dioxide was a major component.

Effect of Thermal Oxidation Temperature on the Properties of Micro-Arc Oxidation Ceramic Coating on TC4 Alloy

2016 ◽  
Vol 697 ◽  
pp. 623-626
Author(s):  
Er Xin Ni ◽  
Ji Kang Yan ◽  
Yun Feng Wu ◽  
Yuan Teng ◽  
Zhi Cao Duan ◽  
...  
Keyword(s):  
Phase Composition ◽  
Surface Morphology ◽  
Thermal Oxidation ◽  
Ceramic Coating ◽  
Oxidation Temperature ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Coating Surface ◽  
Tc4 Alloy ◽  
Micro Arc Oxidation

The effect of thermal oxidation temperature on the properties of MAO ceramic coating was investigated, The phase composition and surface morphology of composite oxidation coating were analyzed by XRD and SEM. The micro-hardness of composite oxidation coating were tested by micro hardness tester. The results shown that the composite oxidation coating consists of rutile, anatase Ti and HA. With the thermal oxidation temperature increasing, the micro-hardness of composite oxidation coatings were improved, but when the thermal oxidation temperature rose from 600 °C to 700 °C, the micro-hardness of coating dropped from 575 HV to 505 HV. With the thermal oxidation temperature increasing, the numbers of micro-porous on coating surface was decreased , and the composite oxidation coating became more density.

Preparation and Performance of Ceramic Coatings Formed by Micro Arc Oxidation on Titanium Alloy

2008 ◽  
Vol 375-376 ◽  
pp. 323-327
Author(s):  
Ying Xue Yao ◽  
Li Qun Li ◽  
Jian Jun Xi
Keyword(s):  
Titanium Alloy ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Dense Layer ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
Tc4 Titanium Alloy ◽  
Micro Arc Oxidation ◽  
Anodic Voltage ◽  
And Performance

The effect of technological parameters on MAO ceramic coating were investigated through the technique of micro-arc oxidation (MAO) on TC4 titanium alloy and. Microstructure and morphology of coatings were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result shows that electric parameters and compositions of the electrolyte have notable effects on the growth of MAO ceramic coatings. The cathodic and anodic voltage rise gradually with the oxidation time increasing. The growth rate of ceramic coating is fast at the beginning, and then turns slowly. The ceramic coatings can be divided into three layers from interior to exterior, such as the transition layer, the dense layer and the porous layer. The coating is mainly composed of rutile and anatase and combined with the substrate firmly. The ceramic coating’s composition in inner and outer layers appears quite different. The ceramic coating on titanium alloy is of excellent performance on anti-attrition and anti-corrosion.

A Preliminary Study of Anodization and Electroless Ni–P Plating on AZ80 Magnesium Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 663-666 ◽  
Author(s):  
Ping Shi ◽  
Xue Dong Han
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Modifications ◽  
Atomic Ratio ◽  
Az80 Magnesium Alloy ◽  
Micro Arc Oxidation ◽  
Preliminary Study ◽  
Electroless Ni

Magnesium alloys are being used as structural components in industry because of their high strength to weight ratio. But their high electrochemical activity and poor corrosion resistance limited their applications. Therefore, surface modifications are needed for protection purpose. This paper studied the anodic micro-arc oxidation and electroless Ni-P plating surface modifications on AZ80 magnesium alloy. The SEM, XRD and EDS were used to characterize the surface coating. It shows that a micro-porous MgO layer with the pores size 5 – 20 μm was fabricated on the bare magnesium alloy. The nodule Ni-P deposition could be prepared on the out layer of MgO with Ni/P atomic ratio being 1.4. The pores in MgO layer could be sealed by the following Ni-P deposition. Therefore the corrosion resistance of the magnesium alloy could be further improved.

Variable Parameter Processes of Micro-Arc Oxidation for Aluminium Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1273-1278
Author(s):  
Cheng Gao ◽  
Jin Yong Xu ◽  
Xuan Yi Shi ◽  
Ya Juan Liu ◽  
Jing Chun Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Wear Rate ◽  
Ceramic Coating ◽  
Early Stage ◽  
Variable Parameter ◽  
Ceramic Coatings ◽  
Constant Current ◽  
Constant Voltage ◽  
Micro Arc Oxidation ◽  
The Way

In micro-arc oxidation process, ceramic coating had a rapid growth all along by the way of constant current oxidation, and ceramic coating had a low roughness by the way of constant voltage oxidation. But few research focus on the mixed control process of constant current oxidation and constant voltage oxidation. In this paper we propose a variable parameter process that can combine the advantages of constant current and constant voltage oxidation for the first time. The growth kinetics of different technics was analyzed according to the change law of current and voltage. Surface topographs of ceramic coating were observed using scanning electron microscopy (SEM). The friction tests were carried out using a self-made friction tester. The results show that ceramic coating has an upper growth rate and a low roughness by the process of constant current+constant voltage oxidation. The ceramic coating has a high growth rate by process of constant voltage+constant current oxidation. The results of friction test indicate that the wear rate and roughness of ceramic coating are positive correlation at early stage of friction. While the ceramic coatings treated by different technics have the close wear rate at stable friction stage, which embodies the inner layer of ceramic coating has a well antiwear behavior.

scholarly journals SURFACE MODIFICATION OF TITANIUM DIOXIDE NANOPARTICLES WITH ACRYLIC ACID/ISOBUTYLENE COPOLYMER UNDER ULTRASONIC TREATMENT

2019 ◽  
Vol 16 (32) ◽  
pp. 338-344
Author(s):  
Nikolay A. BULYCHEV ◽  
Lev N. RABINSKIY
Keyword(s):  
Titanium Dioxide ◽  
Surface Modification ◽  
Composite Materials ◽  
Acrylic Acid ◽  
Ultrasonic Treatment ◽  
Titanium Dioxide Nanoparticles ◽  
Polymer Coatings ◽  
Pigment Surface ◽  
Electrokinetic Sonic Amplitude ◽  
Modification Of Titanium

The influence of the ultrasonic treatment of block copolymer solution on its solid-liquid interface behavior was investigated in detail. The surface modification of titanium dioxide nanoparticles in aqueous dispersions of specially tailor-made periodic acrylic acid/isobutylene copolymer by ultrasonic treatment was studied in order to get new approaches for the creation of hybrid composite materials or polymer coatings. The pigment surface modification by the above copolymer was comparatively investigated regarding conventional adsorption as contrasted to an ultrasonic treatment assisted procedure. The course and efficiency of the polymer adsorption onto the pigment surface were quantified by electrokinetic sonic amplitude measurements. The higher efficiency of the pigment surface coating by the copolymer as achieved by ultrasonic treatment in comparison to conventional adsorption is a consequence of ultrasonically induced pigment surface activation. Two perspective avenues of the utilization of the discovered effects for creation of organic-inorganic composite materials are anticipated: the nanoparticles could first be treated by ultrasound in the presence of polymers and so create a surface modifying coating and the second option is an entrainment of the nanoparticles into the monomer matrix which can be polymerized afterward yielding a polymer with immobilized nanoparticles.

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