Study on the Preparation and Property of the Ceramic Film on the LY12 Aluminium Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 223-227
Author(s):  
Xiao Wen Chen ◽  
De Fen Zhang
Keyword(s):  
Thin Film ◽  
Aluminum Alloy ◽  
Aluminium Alloy ◽  
Current Density ◽  
Microarc Oxidation ◽  
Ceramic Film ◽  
Potentiostatic Method ◽  
Ceramic Thin Film ◽  
Micro Arc Oxidation

The ceramic thin film on the surface of LY12 aluminum alloy were prepared by the method of the microarc oxidation. The appearance of film was observed by stereoscopic microscope, the thickness of film was tested used thickness tester and the corrosion resisting property of sample in solution of 3.5% NaCl was measured by potentiostatic method. The results show that the tightness of film is best when used 8A/ dm2for micro-arc oxidation, the hardness is increased with the increase of current density. The corrosion resisting property of ceramic film in solution of 3.5% NaCl used different current density is different, the corrosion resisting property of ceramic film is first increased and then decreased with the increase of current density, the corrosion resisting property of ceramic film prepared with the current density of 8A/ dm2is best.

Study On the Corrosion Resistance Properties of the Ceramic Coating Obtained Through Microarc Oxidation on the Aluminium Alloy Surface

2007 ◽  
Vol 353-358 ◽  
pp. 1733-1736 ◽  
Author(s):  
Fei Chen ◽  
Hai Zhou ◽  
Chen Chen ◽  
Fan Xiu Lu ◽  
Fan Xiu Lu
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Ceramic Coating ◽  
Microarc Oxidation ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Α Al2o3

Oxidation ceramic coating was directly synthesized on LY12 aluminium alloy by micro-arc oxidation (MAO) process in Na2SiO3 electrolyte solution with the Na2WO4-KOH-Na2EDTA addition. The corrosion resistance of the coating was tested using CS300P electrochemical corrosion workshop in 3.5% NaCl solution. Using the scanning electron microscopy (SEM) and X-ray diffraction (XRD), the cross-section microstructure, the surface morphology and the phase structure of the micro-arc oxidation ceramic coating were analyzed. The results showed that the corrosion resistance of the micro-arc oxidation ceramic coating in 3.5% NaCl solution was enhanced remarkably, the corrosion velocity was obviously slowed down. The thickness of micro-arc oxidation ceramic coating was about 11μm. The final phases in the coating were found to be α-Al2O3 and γ-Al2O3. The mechanism of the oxidation ceramic coating formation was investigated too.

Effects of polyvinylidene fluoride sealing on micro-arc oxidation coating of 7075 aluminum alloy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J. Li ◽  
R.G. Song ◽  
X. Qi ◽  
C. Wang ◽  
B. Jiang
Keyword(s):  
Aluminum Alloy ◽  
Polyvinylidene Fluoride ◽  
Microarc Oxidation ◽  
Pvdf Film ◽  
7075 Aluminum Alloy ◽  
Alloy Matrix ◽  
Content Type ◽  
Micro Arc Oxidation ◽  
Oxidation Technology ◽  
And Performance

Purpose The purpose of this is to study the effects of organic sealing on the structure and performance of the micro-arc oxidation (MAO) film of 7075 aluminum alloy. Design/methodology/approach The 7075 aluminum alloy was treated by micro-arc oxidation technology, then the MAO films were sealed by polyvinylidene fluoride (PVDF) solutions with different concentrations to forms a MAO/PVDF composite coating on the surface of the 7075 aluminum alloy matrix. Findings The results show that the MAO/PVDF film thickness increased to 24.8 um. When the PVDF concentration was 8 g/L, and the sealed film reached best corrosion resistance and wear resistance. Originality/value The effects of different concentrations of PVDF on microarc oxidation properties of 7075 aluminum alloy were studied.

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.

Features of physical and geometrical model of the formation of porous structures of oxide films with micro-arc oxidation of aluminum piston alloys

2017 ◽  
Vol 14 (4) ◽  
pp. 200-207
Author(s):  
M. L. Scriabin ◽  
I. N. Smekhova
Keyword(s):  
Aluminum Alloy ◽  
Surface Hardening ◽  
Oxide Films ◽  
Microarc Oxidation ◽  
Geometrical Model ◽  
Aqueous Electrolytes ◽  
High Porosity ◽  
Porous Structures ◽  
Mechanism Of Formation ◽  
Micro Arc Oxidation

Тhe article considers one of the promising methods of surface hardening of piston aluminum alloy - microarc oxidation. The schemes of formation of the barrier and outer layers surface treatment in aqueous electrolytes. Shows the mechanism of formation of the interface. Considers the formation of layers with high porosity and method of exposure. Proposed and described the conditions of formation of oxide films on the surface of the piston on the basis of physico-geometrical model of Keller and identified their characteristics.

Effects of Current Density on the Properties of Microarc Oxidation Coatings Formed on Aluminum Alloy in Silicate-Na2MoO4 Electrolyte

2015 ◽  
Vol 814 ◽  
pp. 398-403 ◽  
Author(s):  
Ping Wang ◽  
Ting Wu ◽  
Xiao Yang Guo ◽  
Ya Peng
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Polarization Curve ◽  
Current Density ◽  
Microarc Oxidation ◽  
Discharge Process ◽  
Micropore Size

Microarc oxidation (MAO) coatings on ZL108 aluminum alloy were prepared in the silicate-Na2MoO4 electrolytes with different current density. The MAO process was studied by measuring the voltage as a function of time. The microstructure, compositions, distribution of element and corrosion resistance of the MAO coatings were investigated by SEM, XRD, EDS, XPS and polarization curve, respectively. With the increasing of current density, the final voltage in the microarc discharge process increased. The results shown that the MAO coatings were mainly composed of mullite, γ-Al2O3, Si, little MoO2 and MoO3. The micropore size, thickness, compositions, distribution of element of the MAO coatings depended on the current density and the amount of MoO2 and MoO3. The corrosion resistance improved as the porosity of the MAO coatings decreasing.

scholarly journals Effect of current density on physical and chemical properties of microarc oxidation coatings of aluminium alloy

2005 ◽  
Vol 54 (12) ◽  
pp. 5743
Author(s):  
Wu Han-Hua ◽  
Wang Jian-Bo ◽  
Long Bei-Yu ◽  
Lyu Xian-Yi ◽  
Long Bei-Hong ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Current Density ◽  
Microarc Oxidation ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Growth Processes of AC Powered Micro-Arc Oxidation Ceramic Film on Aluminum Alloy

2014 ◽  
Vol 697 ◽  
pp. 7-11 ◽  
Author(s):  
Jin Ma
Keyword(s):  
Aluminum Alloy ◽  
Oxide Film ◽  
Porous Structure ◽  
Ceramic Oxide ◽  
Ceramic Film ◽  
Ac Power ◽  
Voltage Change ◽  
Third Stage ◽  
Micro Arc Oxidation ◽  
Film Producing

Micro-arc oxidation technique was studied on the surface of 2A12 aluminum alloy using AC power in this paper. The micro-arc oxidation process was divided into several periods to investigate the changes of thickness and surface morphology of oxide film that forms in different periods and record the voltage change between oxide film. The following conclusions have been found: The growth of oxide film can be divided into three stages, the first stage is the formation and disruptive discharge of amorphous oxide film, producing the ceramic oxide granules; the second stage is the formation of ceramic oxide film, the ceramic oxide granules turns into porous structure oxide film in this stage; the third stage is the growth of ceramic oxide film, the gas film forms in the oxide film’s porous structure is electric broken-down, leading higher energy discharged by micro-arc, which becomes a significant reason for promoting the growth of ceramic film.

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