The Preparation and Performance of LC4 Aluminum Alloys Ceramic Coatings with Trace Loose Layer Treated by Micro-Arc Oxidation

2014 ◽  
Vol 528 ◽  
pp. 3-7
Author(s):  
Jun Zhao ◽  
Jian Jun Xi ◽  
Chun Ping Zhao ◽  
Yu Jia Sun
Keyword(s):  
Aluminum Alloy ◽  
Mechanical Characteristics ◽  
Mechanical Performance ◽  
Ceramic Coatings ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
And Performance ◽  
High Temperature Erosion ◽  
Loose Layer ◽  
Performance Structure

LC4 aluminum alloy samples were treated by micro-arc oxidation (MAO) to produce trace loose layer film to improve the surface properties. The mechanical characteristics, high temperature erosion performance, structure and composition were investigated by strength tester, high flame erosion, scanning electron microscopy and energy-dispersive X-ray spectrometry. Compared to the untreated aluminum alloy, MAO coatings have good mechanical performance with tensile strength bigger than 18MPa and is intact with 20s heat ablation of 1900°C.

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.

Effects of Al2O3 Nanoparticles on Microstructure and Performance of Ceramic Coatings by Micro-Arc Oxidation

2013 ◽  
Vol 537 ◽  
pp. 92-96
Author(s):  
Yu Jun Yin ◽  
Shu Hua Li ◽  
Da Wei Shen ◽  
Yuan Yuan Zu ◽  
Chang Zheng Qu
Keyword(s):  
Aluminum Alloy ◽  
Oxide Coating ◽  
Ceramic Coatings ◽  
Al2o3 Nanoparticles ◽  
Electrolytic Solution ◽  
Dense Ceramic ◽  
Micro Arc Oxidation ◽  
And Performance ◽  
Microstructure And Performance ◽  
Ceramic Oxide Coating

A dense ceramic oxide coating approximately 45 µm thick was prepared on a Ly12 aluminum alloy by micro-arc oxidation in an alkali-phosphate electrolytic solution. Coating thickness and surface roughness (Ra) were measured after the coating had been synthesized. The effects of Al2O3 Nanoparticles in electrolyte on phase composition, microstructure and microhardness of the micro-arc oxidation ceramic coatings on Ly12 aluminum alloy were investigated by means of XRD, SEM and hardness experimentation. The results show that the ceramic coatings become more dense and its microhardness increased by adding Al2O3 Nanoparticles in electrolyte. In addition, the roughness of the micro-arc oxidation ceramic coatings is obviously improved by addition of Al2O3 Nanoparticles.

Effect of oxidation time on the microstructure and properties of ceramic coatings prepared by microarc oxidation on 7A04 superhard aluminum alloy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744026
Author(s):  
Feng Xiao ◽  
Hui Chen ◽  
Jingguo Miao ◽  
Juan Du
Keyword(s):  
Aluminum Alloy ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Ceramic Layer ◽  
X Ray Diffraction ◽  
Oxidation Treatment ◽  
X Ray ◽  
Metallurgical Bonding ◽  
Dense Ceramic ◽  
Morphology Of Surface

Under the sodium aluminates’ system, microarc oxidation treatment was conducted on the superhard aluminum alloy 7A04 for different times. The microstructure of microarc oxidation ceramic layer was investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influences of different oxidation times on the adhesion strength of ceramic layer and substrate, the morphology of surface and cross-section, the phase composition and the electrochemical properties were studied. The results indicated that the connection of the coating and substrate appears to be metallurgical bonding and dense ceramic layer, and the surface is in a “volcanic vent” morphology, which is composed of [Formula: see text]-Al2O3 and little [Formula: see text]-Al2O3. The corrosion resistance of ceramic layer is improved significantly in contrast with that of the substrate.

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.

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 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.

Microstructure and properties of rare earth CeO2-doped graphene composite coatings prepared by MAO on AA7050

2020 ◽  
Vol 111 (11) ◽  
pp. 923-930
Author(s):  
Yu Zong ◽  
Renguo Song ◽  
Tianshun Hua ◽  
Siwei Cai
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Composite Coatings ◽  
High Strength ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Doped Graphene ◽  
Micropore Size

Abstract In this paper, ceramic coatings were prepared on the surface of 7050 high strength aluminum alloy using a micro-arc oxidation process in a silicate electrolyte combined with the rare earth element cerium or graphene. To analyze the surface morphology, roughness, phase composition, and corrosion resistance, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, and electrochemical measurements were used, respectively. It was shown that the micropore size of the composite coatings, which mainly consisted of α-Al2O3 and γ-Al2O3, decreases and the density improved with the simultaneous addition of 4 g · L-1 of CeO2 and 10 g · L-1 of graphene to the electrolyte. In addition, with the addition of CeO2 and graphene, the roughness was the lowest and the corrosion resistance was significantly improved.

Influences of Calcination Ambiences on Morphologies, Phase Composition and Contents of the Elements of Ceramic Coatings on Ti Alloy by Micro-Arc Oxidation

2012 ◽  
Vol 512-515 ◽  
pp. 1066-1069
Author(s):  
Jin Xue Zhang
Keyword(s):  
Electron Microscopy ◽  
Phase Composition ◽  
Ceramic Coatings ◽  
Ti Alloy ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Oxidation Properties ◽  
Α Al2o3 ◽  
Scanning Electron

Compound ceramic coatings with the main crystal phase of Al2TiO5 (as-coated samples) were prepared in situ on the surface of Ti-6Al-4V alloy by means of pulsed bi-polar micro-arc oxidation (MAO) in an NaAlO2 solution. The coated samples were calcined in argon and air at 1000 oC, respectively. The phase composition, surface and section morphology, and element contents of the ceramic coatings were investigated by X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (XRF). The samples were treated in argon and the as-coated ones were calcined in air at 1000 oC to study the anti-oxidation properties of the samples. The results show that Al2TiO5 had been decomposed in an hour and transformed into α-Al2O3 and rutile TiO2 in air. However, Al2TiO5 had been decomposed in four hours in argon and the final coating surface was completely composed of α-Al2O3. The content of Al2O3 was decreased from outside to inside layers and Ti2O3 was formed in the coating. Furthermore, the morphology of the ceramic coatings after the calcination was different. The coatings calcined in argon were finer; the grains and pores were smaller than those in air.

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