Influence of the current density on CaP coating growth during the US-assisted micro-arc oxidation

2020 ◽  
Author(s):  
E. A. Kazantseva ◽  
E. G. Komarova
Keyword(s):  
Current Density ◽  
The Us ◽  
Micro Arc Oxidation ◽  
Coating Growth

scholarly journals Effect of power of ultrasound during micro-arc oxidation on morphology, elemental and phase composition of calcium phosphate coatings

2021 ◽  
Vol 2064 (1) ◽  
pp. 012057
Author(s):  
E A Kazantseva ◽  
E G Komarova
Keyword(s):  
Phase Composition ◽  
Oxidation Process ◽  
X Ray ◽  
Phosphate Coatings ◽  
The Us ◽  
Local Destruction ◽  
Structure Heterogeneity ◽  
Micro Arc Oxidation ◽  
Morphological Transformations ◽  
Calcium Phosphate Coatings

Abstract The effect of the magnitude of the US (ultrasound) power applied during the MAO (micro arc oxidation) process on the morphology, elemental and phase composition of the CaP coatings was studied. The US at different power (50-200 W) applying during the MAO process led to the local destruction of the structure elements (spheres and pores) and local filling the pore spaces on the coating surface, and to the formation of local macro-pores inside the coatings near the substrate. Such morphological transformations led to the surface and structure heterogeneity of the coatings, increasing of the surface roughness from 3.0 to 4.5 μm and of the thickness from 50 to 60 μm. The US application at different power did not affect significantly the elemental composition of the coatings. At the same time, under applied US with power more than 100 W, the state of the coatings transformed from X-ray amorphous to the quasiamorphous with the small incorporation of crystalline phases of CaHPO4 and β-Ca2P2O7.

Corrosion Resistance of Mg-4Zn Alloy with Amorphous Micro-Arc Oxidation Coating in Simulated Body Fluid

2016 ◽  
Vol 852 ◽  
pp. 1325-1333
Author(s):  
Li Chen Zhao ◽  
Shuang Jin Liu ◽  
Yu Min Qi ◽  
Chun Xiang Cui
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Current Density ◽  
Polarization Resistance ◽  
Body Fluid ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Metal Substrate ◽  
Electrochemical Measurements ◽  
Micro Arc Oxidation

A binary Mg-4Zn alloy was fabricated as a potential degradable biomaterial. To improve the corrosion resistance of Mg-4Zn alloy, an amorphous micro-arc oxidation (MAO) coating was prepared on the Mg-4Zn substrate. Electrochemical measurements and immersion tests were employed to evaluate the corrosion resistance of the specimen in simulated body fluid (SBF). Electrochemical measurements show that the Mg-4Zn alloy covered with a MAO coating has a much lower corrosion current density and a much greater polarization resistance. Immersion tests suggest that the degradation of Mg-4Zn substrate is relatively serious during the initial 8 h of immersion although it has been protected by a MAO coating. When most micro-pores within the MAO coating have been filled with precipitates resulted from the corrosion of the metal substrate, the degradation of the Mg-4Zn substrate is significantly delayed.

The effects of current density on the phase composition and microstructure properties of micro-arc oxidation coating

2002 ◽  
Vol 345 (1-2) ◽  
pp. 196-200 ◽  
Author(s):  
Yang Guangliang ◽  
Lü Xianyi ◽  
Bai Yizhen ◽  
Cui Haifeng ◽  
Jin Zengsun
Keyword(s):  
Phase Composition ◽  
Current Density ◽  
Micro Arc Oxidation

Preparation and Performance of Micro-Arc Oxidation Ceramic Coating of Titanium Alloy in Low Current Density

2011 ◽  
Vol 335-336 ◽  
pp. 708-712
Author(s):  
Jian Jun Xi ◽  
Jun Zhao ◽  
Guo Jun Niu
Keyword(s):  
Titanium Alloy ◽  
Friction Coefficient ◽  
Surface Morphology ◽  
Current Density ◽  
Ceramic Coating ◽  
Low Power Consumption ◽  
Bipolar Pulse ◽  
Phosphate Silicate ◽  
Micro Arc Oxidation ◽  
And Performance

In this paper, Three types of electrolyte (phosphate, silicate, aluminum) are considered to make preparation for micro-arc oxidation coatings on titanium alloy by bipolar pulse MAO oxidation power with low power consumption (density of current less than 1A/dm2). Treated by micro-arc oxidation, dense micro-arc oxidation ceramic coating is formed on titanium alloy. Surface morphology and friction coefficient of MAO coating is analyzed. The research on the effect of NaF on ablation of MAO coating is prepared, which guides the configuration of the electrolyte later.

Effect of Current Density on the Microstructure and Corrosion Properties of MAO Coatings on Aluminum Alloy Shock Absorber

2018 ◽  
Vol 764 ◽  
pp. 28-38 ◽  
Author(s):  
Yan Shen ◽  
Hong Xiang Wang ◽  
Yi Peng Pan
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Current Density ◽  
Shock Absorber ◽  
Structural Characteristics ◽  
Ceramic Coatings ◽  
Corrosion Performance ◽  
Cathode Voltage ◽  
Corrosion Properties ◽  
Micro Arc Oxidation

In order to improve the corrosion resistance of shock absorber for ships, the alumina ceramic coatings are carried out on the surface of aluminum alloy shock absorber by micro arc oxidation (MAO) technology. The microstructure and anti-corrosion performance of the MAO coatings were investigated experimentally. This paper mainly focuses on the experimental work to determine the effect of current density on the structural characteristics and corrosion resistance of MAO coatings. The results show that the current density has a significant influence on the preparation of MAO coating during the process. The surface of the coating becomes more compact and smooth with the cathode voltage of 7 A.dm-2. Furthermore, the anti-corrosion performance of the MAO coatings can effectively be improved at the current density of 7 A.dm-2.

Effects of CeO2 on Microstructure and Corrosion Performance of the Coatings Prepared by Pulse Micro Arc Oxidation on AZ31B Mg Alloy

2020 ◽  
Vol 20 (8) ◽  
pp. 4778-4786
Author(s):  
Lilu Qin ◽  
Jiamu Huang ◽  
Longlong Hao ◽  
Jun Su ◽  
Niu Ma ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Salt Spray ◽  
Electrochemical Measurement ◽  
Corrosion Current ◽  
Corrosion Performance ◽  
Micro Arc Oxidation ◽  
Micro Morphology

To improve corrosion performance of coatings on AZ31B magnesium alloy, the nano-CeO2 additives were included in Na2SiO3 based electrolyte during process of pulse micro arc oxidation (MAO). The MAO-CeO2 coating was successfully prepared to characterize its structure, micro morphology and composition. The XRD results indicated that MAO-CeO2 coatings were consisted of Mg2SiO4, MgSiO3, MgF2 and CeO2. The intensity of CeO2 peaks increases with increasing nano-CeO2 particles in electrolyte. The number of cracks on MAO-CeO2 coatings exhibited a V-shaped trend with increase in nano-CeO2 content. Meanwhile, the influence of nano-CeO2 on corrosion behavior of MAO-CeO2 coatings is investigated by salt spray test and electrochemical measurement. The corrosion current density of coatings presented same trend and corrosion potential is further studied. The MAO-CeO2 coatings formed in electrolyte with 10 g/L nano-CeO2 showed best corrosion performance which has the lowest corrosion current density of 0.58 nA/cm2 and the highest corrosion potential of - 1269 mVSCE.

Investigation of micro-arc oxidation coating growth patterns of aluminum alloy by two-step oxidation method

2015 ◽  
Vol 356 ◽  
pp. 581-586 ◽  
Author(s):  
Weiping Li ◽  
Zhiyuan Qian ◽  
Xinghua Liu ◽  
Liqun Zhu ◽  
Huicong Liu
Keyword(s):  
Aluminum Alloy ◽  
Growth Patterns ◽  
Oxidation Method ◽  
Micro Arc Oxidation ◽  
Coating Growth
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