Comparison of Two Different Chemical Conversion Coating on Aluminum Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 208-211
Author(s):  
Yan Bo Wu ◽  
Si Si Zeng ◽  
Peng Sun
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Electrochemical Method ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Conversion Coatings ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Chemical Conversion Coating

In this paper, we made two different chemical conversion coatings on aluminum alloy by TiOSO4 and Na2WO4. The morphology of the chemical conversion surface layers were observed by scanning electron microscopy (SEM). The microcosmic phase structures were characterized using X-ray diffraction (XRD). Electrochemical method was used to study the coatings corrosion resistance. The results indicated that the two conversion coatings were crystal structure material, the surface of coating were both show pothole structure. TiOSO4 coating have better corrosion resistance than Na2WO4 coating.

Structure and Corrosion Resistance of Tin Salt Conversion Coating on Aluminum Alloy

2010 ◽  
Vol 129-131 ◽  
pp. 467-471
Author(s):  
Yan Bo Wu ◽  
Si Si Zeng ◽  
Peng Sun
Keyword(s):  
Corrosion Resistance ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Uncoated Sample ◽  
X Ray ◽  
Coating Composition ◽  
Chemical Conversion Coating ◽  
Better Than

A chrome-free chemical conversion coating was prepared using stannous sulfate as the main salt. The morphology of the chemical conversion surface layer was observed by scanning electron microscopy (SEM). Coating composition and the microcosmic phase structure were characterized using energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) respectively. Electrochemical method and dropping test were used to study the coatings corrosion resistance. The results indicated that the tin salts conversion coating is a crystal structure material that composites with Sn-F-O-Al et al., the surface appears as a accumulation of spherical particles, the crystallinity of conversion coating is better than uncoated sample obviously, the corrosion resistance has improved too.

Technical and Performance Study of Ti-W Composite Chemical Conversion Coating on Aluminum Alloy

2010 ◽  
Vol 129-131 ◽  
pp. 819-823
Author(s):  
Yan Bo Wu ◽  
Si Si Zeng ◽  
Peng Sun
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Orthogonal Experiment ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Spherical Particles ◽  
Performance Study ◽  
Uncoated Sample ◽  
X Ray ◽  
Chemical Conversion Coating

Ti-W composite coating was made by chemical conversion method on aluminum alloy. By orthogonal experiment, the optimal coating-forming conditions were the concentration ratio of TiOSO4 and Na2WO4 was 0.3 g/L:0.3 g/L、KMnO4 1.0 g/L、NaF 1.0 g/L、reaction temperature 40°C、reaction time 2min. The morphology of the coating was observed by scanning electron microscopy (SEM). Coating composition and the microcosmic phase structure were characterized using energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) respectively. Electrochemical test was used to study the coatings corrosion resistance. The results indicated that the composite chemical conversion coating is a crystal structure material that composites with Al、Mn、W、Ti et al., its surface appears as a accumulation of fibroid spherical particles, the crystallinity of conversion coating is better than uncoated sample obviously. The corrosion potential of the coating is improved to -0.440V, they were both prove the corrosion resistance has improved.

Corrosion Behavior and Microstructure of Pd Ions Doped Cerium Conversion Coating on AA2219-T87 Aluminum Alloy

2015 ◽  
Vol 1090 ◽  
pp. 79-83
Author(s):  
Yan Hong He ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
Sheng Li Zhu ◽  
Zhao Yang Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Composite Coatings ◽  
Corrosion Current ◽  
Conversion Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Corrosion Resistance

In this paper, Pd ions doped cerium conversion coating (CeCC/Pd) was deposited on AA2219-T87 aluminum alloy by electroplating. The microstructure and composition of the coating were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Corrosion behavior of AA2219-T87 aluminum alloy with the coating was investigated in 3.5wt.% NaCl solution at the room temperature. XRD and XPS results indicate the existence of cerium-oxide and palladium-oxide in the CeCC/Pd. Polarization curves show that the CeCC/Pd exhibits excellent corrosion resistance. The corrosion current density of the CeCC/Pd decreases by two orders of magnitude compared with the CeCC. The improvement of corrosion resistance would be attributed to the small grain size, good compactness and adhesive strength of the composite coatings.

Cerium Chemical Conversion Coating for Aluminum Alloy 2024-T3 and Its Corrosion Resistance

CORROSION ◽  
2004 ◽  
Vol 60 (3) ◽  
pp. 237-243 ◽  
Author(s):  
C. Wang ◽  
F. Jiang ◽  
F. Wang
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Photoelectron Spectroscopy ◽  
Chemical Conversion ◽  
Spherical Particles ◽  
Conversion Coatings ◽  
Nacl Solution ◽  
X Ray ◽  
Golden Yellow ◽  
Aluminum Alloy 2024

Abstract New golden, yellow-colored cerium chemical conversion coatings on aluminum alloy 2024-T3 (AA2024-T3 [UNS A92024]) surface at room temperature were obtained by immersing the alloy into a cerium solution containing zinc chloride (ZnCl2) and hydrogen peroxide (H2O2). Electrochemical methods and immersion tests were used to study the dynamics of the coatings formation and their corrosion resistance in 3.5% sodium chloride (NaCl) solution. The morphologies of the coatings were recorded by scanning electronic microscopy (SEM). Energy-dispersive x-ray (EDX) analysis and x-ray photoelectron spectroscopy (XPS) were used to analyze the chemical composition and the oxidation state of the elements in the coatings. Polarization experiments and immersion tests in 3.5% NaCl solution showed that the sensitivity to pitting corrosion for the conversion-coated AA2024-T3 was greatly lower than that of the untreated specimens, and the corrosion resistance improved markedly. SEM photographs showed that the coatings consisted of a lot of spherical particles. EDX and XPS experimental results showed that the coatings were made up of oxygen, cerium, and aluminum, and the spherical particles contained higher contents of cerium and oxygen than the other sites. Cerium was mainly in the form of Ce4+. The mechanisms of conversion coatings formation and improvement on corrosion resistance also are discussed.

scholarly journals Preparation of Ti–Zr-Based Conversion Coating on 5052 Aluminum Alloy, and Its Corrosion Resistance and Antifouling Performance

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Hehong Zhang ◽  
Xiaofeng Zhang ◽  
Xuhui Zhao ◽  
Yuming Tang ◽  
Yu Zuo
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Aluminum Alloy ◽  
Current Density ◽  
Corrosion Current Density ◽  
Salt Water ◽  
Water Immersion ◽  
Chemical Conversion ◽  
Corrosion Current ◽  
Conversion Coating

A chemical conversion coating on 5052 aluminum alloy was prepared by using K2ZrF6 and K2TiF6 as the main salts, KMnO4 as the oxidant and NaF as the accelerant. The surface morphology, structure and composition were analyzed by SEM, EDS, FT–IR and XPS. The corrosion resistance of the conversion coating was studied by salt water immersion and polarization curve analysis. The influence of fluorosilane (FAS-17) surface modification on its antifouling property was also discussed. The results showed that the prepared conversion coating mainly consisted of AlF3·3H2O, Al2O3, MnO2 and TiO2, and exhibited good corrosion resistance. Its corrosion potential in 3.5 wt % NaCl solution was positively shifted about 590 mV and the corrosion current density was dropped from 1.10 to 0.48 μA cm−2. By sealing treatment in NiF2 solution, its corrosion resistance was further improved yielding a corrosion current density drop of 0.04 μA cm−2. By fluorosilane (FAS-17) surface modification, the conversion coating became hydrophobic due to low-surface-energy groups such as CF2 and CF3, and the contact angle reached 136.8°. Moreover, by FAS-17 modification, the corrosion resistance was enhanced significantly and its corrosion rate decreased by about 25 times.

Formation and Properties of Zr/Ti Based Nano-Sized Non-Chromium Chemical Conversion Coating on AA 5083

2019 ◽  
Vol 19 (6) ◽  
pp. 3487-3494 ◽  
Author(s):  
Bin Liu ◽  
Yi Zhao ◽  
Liang Li ◽  
Yafei Feng ◽  
Zhigang Fang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Acidic Solution ◽  
Salt Spray ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Dense Layer ◽  
Environment Friendly ◽  
Chemical Conversion Coating ◽  
Inhibitive Action ◽  
Nano Size

An environment-friendly non-chromium chemical conversion coating was obtained from fluozirconate/fluotitanate acidic solution for the corrosion protection of AA 5083. The surface morphology, composition, electrochemical behavior and corrosion resistance of this coating were investigated. The coating was found to be a homogeneous and dense layer consisting of nano-size particles, of which the major component was compound oxides consisted by Al, Mg, Zr, Ti, F and O. The results of electrochemical measurements, immersion and natural salt spray (NSS) tests demonstrated that the corrosion resistance of the AA 5083 H-116 was improved by the nano-sized non-chromium chemical conversion coating considerably, which was most attributed to the great inhibitive action on the anodic dissolution by acting as a protective barrier layer.

Formation and corrosion resistance of a phosphate chemical conversion coating on medium carbon low alloy steel

2016 ◽  
Vol 40 (2) ◽  
pp. 1347-1353 ◽  
Author(s):  
Cong-cong Jiang ◽  
Gui-yong Xiao ◽  
Xian Zhang ◽  
Rui-fu Zhu ◽  
Yu-peng Lu
Keyword(s):  
Corrosion Resistance ◽  
Alloy Steel ◽  
Crystalline Structure ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Low Alloy Steel ◽  
Medium Carbon ◽  
Fine Crystalline Structure ◽  
Chemical Conversion Coating

A uniform fine-crystalline structure is obtained upon PCC coating on 35CrMnSi with Fe2+ curing (b).

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.

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