A Study of Micro-Arc Oxidation Coatings on Aluminum Alloy Drill Pipe for Offshore Platform

2017 ◽  
Vol 51 (3) ◽  
pp. 16-22 ◽  
Author(s):  
Yan Shen ◽  
Prasanta K. Sahoo ◽  
Yipeng Pan
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Experimental Work ◽  
Structural Characteristics ◽  
Drill Pipe ◽  
Offshore Platform ◽  
Cathode Voltage ◽  
Micro Arc Oxidation ◽  
Anticorrosion Performance

AbstractIn order to enhance the corrosion resistance of a drill pipe for an offshore platform, micro-arc oxidation (MAO) coatings were deposited on the surface of an aluminum alloy drill pipe by MAO technology. The microstructure and anticorrosion performance of the MAO coatings were investigated experimentally. This paper mainly focuses on the experimental work to determine the influence of cathode voltage on the structural characteristics and corrosion resistance of MAO coatings. The results show that the cathode voltage has a significant effect on the preparation of MAO coating during the process. The surface of the coating becomes more compact and smooth with the increase of the cathode voltage. Furthermore, the anticorrosion performance of MAO coatings can effectively be improved with the increase of cathode voltage.

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.

Effect of Nano-MoS2 Particles on Properties of Micro-Arc Oxidation Coating Prepared on the Surface of Aluminum Alloy Drill Pipe for Offshore Platform

2016 ◽  
Author(s):  
Yipeng Pan ◽  
Yan Shen ◽  
Prasanta K. Sahoo
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Ceramic Membrane ◽  
Drill Pipe ◽  
Offshore Platform ◽  
Nano Particles ◽  
Micro Arc Oxidation ◽  
Oxidation Technology ◽  
Micro Morphology ◽  
Addition Amount

In order to improve the corrosion resistance of the drill pipe, the alumina ceramic membrane is coated on the surface of aluminum alloy drill pipe of offshore platform by micro arc oxidation technology. This paper mainly focuses on the experimental work to determine the effect of the nano-MoS2 content in the solution on the micro morphology, element content and corrosion resistance of the coating. The results show that the amount of nano-MoS2 particles has big influence on the making of micro-arc oxidation (MAO). The thickness of MAO coating is increased with the adding of nano-MoS2 particles. Besides, the size of the coating is first increased then decreased, and the surface of coating become more compact and smooth with the increase of the amount of nano-MoS2 particles. Also, the corrosion resistance of MAO coating is improved as the amount of MoS2 increases. The corrosion rate is decreased from 0.032g.m−2.h−1 to 0.024g.m−2.h−1 when the addition amount of nano-particles increased from 0.5g/L to 2g/L.

A STUDY OF COMPOSITE COATINGS ON 22MnCrNiMo STEEL FOR MOORING CHAIN

2018 ◽  
Vol 25 (03) ◽  
pp. 1850074
Author(s):  
YAN SHEN ◽  
PRASANTA K. SAHOO ◽  
YIPENG PAN
Keyword(s):  
Corrosion Resistance ◽  
Experimental Work ◽  
Structural Characteristics ◽  
Composite Coatings ◽  
Salt Spray ◽  
Corrosion Performance ◽  
Sic Particles ◽  
Pulsed Electrodeposition ◽  
Mooring Chain ◽  
Spray Treatment

In order to enhance the corrosion resistance of mooring chain, the composite coatings are carried out on the surface of 22MnCrNiMo steel for mooring chain by double-pulsed electrodeposition technology using centrifugal force in the rotating device. The microstructure and anti-corrosion performance of the composite coatings have been investigated experimentally. This paper mainly focuses on the experimental work to determine the structural characteristics and corrosion resistance of composite coatings in the presence of nano-SiC. The results show that the presence of nano-SiC has a significant effect on the preparation of composite coating during the process. The surface of the coating becomes compact and smooth at a moderate concentration of nano-SiC particles. Furthermore, the best corrosion resistance of the composite coatings can be obtained when the concentration of nano-SiC particles is 2.0[Formula: see text]g.L[Formula: see text] after salt spray treatment.

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.

EFFECT OF GRAPHITE ADDITIVES IN ELECTROLYTES ON CHARACTERISTICS OF MICRO-ARC OXIDATION COATINGS ON 7E04 ALUMINUM ALLOY

2019 ◽  
Vol 26 (04) ◽  
pp. 1850178 ◽  
Author(s):  
PING WANG ◽  
JUN PU ◽  
YOU TAO XIAO ◽  
WEN JUN HU ◽  
TING WU ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Phase Composition ◽  
Graphite Powder ◽  
Micro Hardness ◽  
Powder Concentration ◽  
Micro Arc Oxidation ◽  
Surface Morphologies

Micro-arc oxidation coatings were fabricated on 7E04 aluminum alloy substrates by micro-arc oxidation (MAO) in the electrolytes with the graphite addition varying from 0 to 8[Formula: see text]g/L (0, 2, 4, 6, 8[Formula: see text]g/L). The effect of graphite concentration on the surface morphologies, micro-hardness, thickness, phase composition and corrosion resistance of coatings was investigated. With the graphite powder concentration increasing, the oxidation voltage decreased gradually and the thickness of coatings firstly dropped down and then went up. It is found that the size of micro-pores and sintered discs declined with increase of graphite concentration. The XRD results indicated that MAO coatings mainly consisted of [Formula: see text]-Al2O3, [Formula: see text]-Al2O3, SiO2 and a little [Formula: see text]-Al2O3. The corrosion resistance of coatings was improved with the addition of graphite powder. The study reveals that the appropriate graphite powder in the electrolytes is essential to promote the performance of the coatings.

scholarly journals Adhesion and Corrosion Resistance of Micro-Arc Oxidation/Polyurethane Composite Coating on Aluminum Alloy Surface

2020 ◽  
Vol 10 (19) ◽  
pp. 6779
Author(s):  
Ruitao Wang ◽  
Hong Xu ◽  
Zhongping Yao ◽  
Chunxiang Li ◽  
Zhaohua Jiang
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Composite Coating ◽  
Sodium Silicate ◽  
Adhesion Strength ◽  
Waterborne Polyurethane ◽  
Alloy Surface ◽  
Polyurethane Composite ◽  
Micro Arc Oxidation ◽  
Aluminum Alloy Surface

The adhesion and bonding performance of waterborne polyurethane (PU) coating on aluminum alloy surface was improved in this study. To achieve this objective, the effects of different sodium silicate concentrations on the aluminum alloy micro-arc oxidation (MAO) layer and the adhesion strength and corrosion resistance of MAO-PU composite coating before and after modification by MAO treatment of the 7050 aluminum alloy were studied. The experimental results showed that the modification of the MAO membrane layer by a silane coupling agent could significantly improve the adhesion strength and corrosion resistance of the composite coating. Moreover, the maximum adhesion strength was obtained when the concentration of sodium silicate was 12 g L−1.

Effect of Micro Arc Oxidation Treatment on the Corrosion and Stress Corrosion Cracking (SCC) Behaviours of AA7020-T6 Aluminum Alloy in 3.5% NaCl Solution

2015 ◽  
Vol 830-831 ◽  
pp. 639-642
Author(s):  
A. Venugopal ◽  
P. Ramesh Narayanan ◽  
S.C. Sharma ◽  
Koshy M. George
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Alumina Coating ◽  
Slow Strain Rate Test ◽  
Nacl Solution ◽  
Cracking Resistance ◽  
Micro Arc Oxidation

Alumina coating was formed on AA7020 aluminum alloy by micro arc oxidation (MAO) method and its corrosion and stress corrosion cracking (SCC) behaviors were examined in 3.5 wt. % NaCl solution. Potentiodynamic polarization (PP) was used to evaluate the corrosion resistance of the coating and slow strain rate test (SSRT) was used for evaluating the environmental cracking resistance in 3.5% NaCl solution. Results indicated that MAO coating on AA7020 alloy significantly improved the corrosion resistance. However the environmental cracking resistance was found to be only marginal. Key words: aluminum, micro arc oxidation, x-ray diffraction, stress corrosion cracking

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