scholarly journals The Durability of an Organic–Inorganic Sol–Gel Interlayer in Al-GFRP-CFRP Laminates in a Saline Environment

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2362 ◽  
Author(s):  
Barbara Surowska ◽  
Monika Ostapiuk ◽  
Patryk Jakubczak ◽  
Magda Droździel
Keyword(s):  
Aluminum Alloy ◽  
Salt Spray ◽  
Sol Gel ◽  
Exposure Period ◽  
Open Circuit ◽  
Fiber Reinforced Polymers ◽  
Metal Composite ◽  
Neutral Salt ◽  
Fiber Reinforced ◽  
Ambient Temperatures

The aim of the study was to assess the selected properties of a hybrid organic–inorganic silane sol–gel coating (HSG) used in hybrid fiber metal laminates (FML) in a corrosion environment. The HSG coating on the aluminum alloy was produced using 3M™ AC130-2 formulation consisting of 3-glycidoxypropyl-trimethoxysilane (GPTMS) and tetra-n-propoxyzirconium (zirconium(IV) propoxide) (TPOZ). Laminates consisted of aluminum alloy AA2024-T3 sheets, with carbon fiber reinforced polymers (CFRPs) and a glass fiber reinforced metal–composite structure (GFRP). Potentiodynamic and polarization curve and impedance (EIS) tests were carried out on HSG at ambient temperatures after 1 h and 150 h of soaking. Neutral 0.5 M NaCl and 0.8 M NaCl solutions were used for open circuit potential (OCP) and potentiodynamic tests, and 0.5 NaCl was used for the EIS test. A neutral salt spray (NSS) test was applied to laminates with a 12 week exposure period. The results obtained revealed that the HSG coating did not provide sufficient protection against corrosion of the aluminum alloy in direct contact with an aggressive environment but was effective as an interlayer. Local aluminum sheet perforation did not lead to delamination at the metal–composite interface regardless of the type or configuration of the composite. This confirms the durability of HSG used in FMLs.

Effect of Sol-Gel Film on the Corrosion Resistance of Low Carbon Steel Plate

2020 ◽  
Vol 984 ◽  
pp. 43-50
Author(s):  
Hua Yuan Zhang ◽  
Can Wang ◽  
Bing Xue ◽  
Jing Luo
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Steel Plate ◽  
Salt Spray ◽  
Sol Gel ◽  
Low Carbon Steel ◽  
Corrosion Current ◽  
Neutral Salt ◽  
Low Carbon ◽  
Gel Film

To improve the corrosion resistance on Q235 low carbon steel, in this paper, tetraethyl orthosilicate (TEOS), N-dodecyl trimethoxysilane and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) were used to make organic-inorganic hybrid sol-gel film. Cross cut test adhesion method, neutral salt spray test, electrochemical test and film protective efficiency were taken to value the corrosion resistance property. The corrosion topography was studied by optical microscope. In addition, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) curves and equivalent electric circuit fitting were used to analyze the corrosion mechanism. The cross cut adhesion of sol-gel film can reach 1 class and the protection class can attain 5 class after 72 hours neutral salt spray test. According to the potentiodynamic polarization curve analysis, the corrosion potential of sol-gel film coating sample after 0.5 hours immersion was -0.46 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.74×10-7 A·cm-2. The corrosion potential of bare Q235 low carbon steel plate after 0.5 hours immersion was -0.78 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.75×10-6 A·cm-2. The impedance value on 0.1 Hz (|Z|0.1Hz) (1.27×106 Ω·cm2) of sol-gel film coating sample was more than three orders of magnitude higher than the value of the low carbon steel plate. Even dipping in 3.5 wt. % NaCl for 72 hours, the |Z|0.1Hz value of sol-gel coating sample was still one order of magnitude higher than the low carbon steel plate with 0.5 hours immersion. Sol-gel film with excellent adhesion can significantly improve the corrosion resistance of low carbon steel plate. Sol-gel film can increase the protection efficiency of low carbon steel plate by 90%.

Galvanic Formation of Zn-Ni/Zn-Co Type Multilayer Alloy Coatings on Steel Substrate

2015 ◽  
Vol 227 ◽  
pp. 147-150
Author(s):  
Agnieszka Nagrabia ◽  
Maciej Sowa ◽  
Wojciech Simka ◽  
Artur Maciej
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Steel Substrate ◽  
Salt Spray ◽  
Open Circuit ◽  
Neutral Salt ◽  
Weight Changes ◽  
Corrosion Properties ◽  
Potential Measurement ◽  
Layer Coating

Zn-Ni and Zn-Co monolayer and Zn-Ni/Zn-Co multilayer (from 2 to 128 layers) alloy coatings were formed on steel substrate by electrodeposition from acidic Zn-Ni bath and neutral Zn-Co bath. Samples were tested in salt chamber for corrosion resistance in neutral salt spray. Open circuit potential measurement and gravimetric study of corrosion were carried for samples immersed in the 5% NaCl solution.It was found that coatings of Zn-Ni surface layer occurred higher corrosion resistance then the coatings of Zn-Co surface layer. Sixteen-layer coating with Zn-Ni surface layer proved to be most effective in protecting the steel substrate. Zn-Ni monolayer showed the lowest corrosion potential, which affects the corrosion properties. Sample weight changes during exposure to a corrosive environment are related to digestion of the coating and the formation of corrosion products.

scholarly journals Comparative Study on the Corrosion Resistance of 6061Al and SiC3D/6061Al Composite in a Chloride Environment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7730
Author(s):  
Liang Yu ◽  
Shuangshuang Hao ◽  
Xiaodong Nong ◽  
Xiuling Cao ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Specific Area ◽  
Open Circuit ◽  
Pressure Casting ◽  
Neutral Salt ◽  
Salt Leaching ◽  
Chloride Environment ◽  
Al Matrix

Interface problems and the destruction of the continuity of the oxide film in the Al matrix usually reduce the corrosion resistance of the material. In this paper, the corrosion resistance of Al matrix composites (AMCs) was improved by introducing the silicon carbide skeletons (SiC3D) obtained with polymer replica technology. SiC3D/6061Al was fabricated by infiltrating molten 6061Al alloy in the oxidized SiC3D using the low-pressure casting method. The corrosion resistance performances of 6061Al and SiC3D/6061Al in NaCl solution were studied by electrochemical, neutral salt spray corrosion (NSS), and salt leaching (SL) tests. Results show corrosion resistance of SiC3D/6061Al is higher than that of 6061Al alloys by open circuit potential (OCP), potentio-dynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) tests. However, NSS and SL tests show the corrosion resistance of SiC3D/6061Al is lower than that of 6061Al alloy. The reason is a corrosion resistant and anti-oxidation network macrostructure with large interface recombination, few concentrated interfaces, and a small specific area that formed in SiC3D/6061Al. SiC3D cannot damage the continuity of the Al2O3 passivating film, and the network macrostructure greatly improves the corrosion resistance performance.

Hybrid sol-gel coating incorporated with TiO2 nanosheets and anti-corrosive effects on AA2024-T3

2019 ◽  
Vol 66 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Dongdong Peng ◽  
Kang Huang ◽  
Yuntao He ◽  
Zhan Zhang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloy ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Sol Gel ◽  
Corrosion Current ◽  
Corrosion Resistant ◽  
Content Type ◽  
Tio2 Nanosheets ◽  
Loading Amount

Purpose This paper aims to improve the anti-corrosive properties of aluminum alloy AA2024-T3 by coating of hybrid sol-gel coating incorporated with TiO2 nanosheets and to investigate the effect of nanosheets’ size on the improvement of corrosion-resistant performance. Design/methodology/approach A series of hybrid sol-gel films incorporated with varying amounts of TiO2 nanosheets were developed to enhance the corrosion protection performance of the bare metal. Scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to investigate the structure and morphology of the coatings obtained. In addition, the corrosion-resistant properties of the coatings were evaluated using salt spray test and electrochemical impedance spectroscopy. Findings The corrosion current was as low as 9.55 × 10-4 µA/cm2 and optimal positive corrosion potential reached −0.6 V when the size and loading amount of TiO2 nanosheet were optimized, resulting in a remarkable improvement in anti-corrosive properties. Originality/value This work first investigates the effect of incorporation of TiO2 nanoparticles on hybrid sol-gel coating on the improvement of anti-corrosive performance of aluminum alloy AA2024-T3.

scholarly journals Effect of Plasma Surface Pretreatment on Ce3+-Doped GPTMS-ZrO2 Self-Healing Coatings on Aluminum Alloy

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
N. Kumar ◽  
A. Jyothirmayi ◽  
R. Subasri
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Condensation Reaction ◽  
Salt Spray ◽  
Neutral Salt ◽  
Self Healing ◽  
Surface Pretreatment ◽  
Plasma Surface ◽  
Coating Deposition

A hybrid sol synthesized from an acid-catalyzed hydrolysis and condensation reaction of 3-glycidoxypropyltrimethoxysilane (GPTMS) and zirconium n-propoxide was used as a matrix nanocomposite sol. To this sol, 0.01 M Ce3+ was added as an inhibitor to provide a self-healing coating system. The effect of an atmospheric air plasma surface pretreatment of aluminum alloy substrates prior to coating deposition of Ce3+-doped/undoped GPTMS-ZrO2 sol was studied with respect to corrosion protection. Coatings were generated by a dip coating technique employing a withdrawal speed of 5 mm/s and thermally cured at 130° C for 1 h. The coated Al surfaces were characterized using potentiodynamic polarization studies and electrochemical impedance spectroscopy. They were also subjected to accelerated corrosion testing using neutral salt spray test with 5% NaCl solution after creating an artificial scratch for more than 200 hours to assess the self-healing ability of coatings. It was observed that cerium (III) doping was effective for corrosion protection during long-term exposure to the electrolyte solution, and a plasma surface pretreatment of substrates prior to coating deposition of Ce3+-doped coatings improved the adhesion of coatings that provides enhanced corrosion protection along with self-healing ability exhibited in case of damages/scratches caused in the coating.

Corrosion behavior of the joints of carbon fiber reinforced polymers with DP590 steel and Al6022 alloy

2019 ◽  
Vol 66 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Chi Zhang ◽  
Dajiang Zheng ◽  
Guang-Ling Song ◽  
Yang Guo ◽  
Ming Liu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Crevice Corrosion ◽  
Galvanic Corrosion ◽  
Salt Spray ◽  
Corrosion Damage ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Galvanic Current ◽  
Content Type ◽  
Carbon Fiber Reinforced

Purpose This study aims to propose a simple experimental method to distinguish the galvanic corrosion, crevice corrosion and self-corrosion in metal/carbon fiber reinforced polymer (CFRP) joints. Design/methodology/approach The corrosion behaviors of four different galvanic couples, whose anodes were Zn-coated DP590 steel and Al 6022, and cathodes were two kinds of CFRP, were investigated in immersion and GMW14872 cyclic conditions. Findings The results showed that the galvanic corrosion caused by direct contact between CFRP and metals was more serious than that caused by the jointing bolts. The corrosion damage caused by crevice corrosion was severer than that caused by galvanic corrosion. Self-corrosion was also significant, particularly under the cyclic salt spray condition. Practical implications Cyclic salt spray test may more reliably simulate the galvanic corrosion of a joint in industrial service environments, and real corrosion damage may be underestimated by a galvanic current measurement. Originality/value A deeper understanding of different corrosion mechanisms involved in CFRP/metal joints under different service conditions in industry has been given.

Corrosion behavior of 2A12 aluminum alloy in neutral salt spray environment with different Al-clad removing processes

2011 ◽  
Vol 64 (3) ◽  
pp. 207-211 ◽  
Author(s):  
H. C. Liu ◽  
H. P. Xu ◽  
L. Q. Zhu ◽  
J. Z. Liu ◽  
X. B. Ye ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
Salt Spray ◽  
Neutral Salt

scholarly journals Perfect Combination of LBL with Sol–Gel Film to Enhance the Anticorrosion Performance on Al Alloy under Simulated and Accelerated Corrosive Environment

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 111 ◽  
Author(s):  
Xia Zhao ◽  
Shuai Yuan ◽  
Zuquan Jin ◽  
Binbin Zhang ◽  
Nazhen Liu ◽  
...  
Keyword(s):  
Salt Spray ◽  
Sol Gel ◽  
Chloride Ions ◽  
Al Alloy ◽  
Layer By Layer ◽  
Neutral Salt ◽  
Multilayered Coatings ◽  
Multilayered Coating ◽  
Gel Film ◽  
Anticorrosion Performance

Given their outstanding versatile properties, multilayered anticorrosion coatings have drawn great interest from researchers in the academic and engineering fields. However, the application of multilayered coatings is restricted by some limitations such as low interlayer compatibilities, the harsh preparation process, etc. This work introduced a composite film fabricated on a 2A12 aluminum alloy surface, including an anodic oxide film, a sol–gel film, and a layer-by-layer (LBL) self-assembling film from bottom to top. The microstructure and elemental characterization indicated that the finish of the coating with the LBL film resulted in a closely connected multilayered coating with a smoother surface. The anticorrosion performance was systematically evaluated in the simulated corrosive medium and neutral salt spray environment. The integrated coating with the LBL film presented an excellent anticorrosion ability with system impedance over 108 Ω·cm2 and a self-corrosion current density two orders of magnitude lower than that of the other coatings. After the acceleration test in a salt spray environment, the multilayered coatings could still show a good protective performance with almost no cracks and no penetration of chloride ions. It is believed that the as-constructed multilayered coating with high corrosive properties and a fine surface state will have promising applications in the field of anticorrosion engineering.

Silane Films Modified with Yttrium Oxide Nanoparticles for Improved Corrosion Resistance of AA6061-T6

CORROSION ◽  
2012 ◽  
Vol 68 (4) ◽  
pp. 045005-1-045005-6
Author(s):  
S.-L. Zhang ◽  
M.-M. Zhang ◽  
Y. Yao ◽  
F. Sun
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Yttrium Oxide ◽  
Salt Spray ◽  
Electrode Reaction ◽  
Neutral Salt ◽  
Physical Barrier ◽  
Sem Images ◽  
Potentiodynamic Polarization Curves ◽  
Surface Morphologies

The present work strives to evaluate the corrosion resistance of aluminum alloy (AA)6061-T6 (UNS A96061) pretreated with bis-1,2-[triethoxysiyl]ethane silane (BTSE) solution containing different contents of yttrium oxide (Y2O3) nanoparticles. The corrosion resistance of the pretreated AA6061-T6 substrates was investigated with potentiodynamic polarization curves and the neutral salt spray (NSS) test. The morphologies of the silane film were observed using scanning electron microscopy (SEM). The results indicated that the presence of small amounts of Y2O3 nanoparticles in BTSE solutions can increase the corrosion resistance of the silane films in 3.5% sodium chloride (NaCl) solution. Y2O3 nanoparticles do not change the behavior of the electrode reaction. The formed silane film acts as a physical barrier for the protection of aluminum alloy. The SEM images indicated that the surface morphologies of silane films formed were flat and compact, when the contents of the Y2O3 nanoparticles in BTSE solutions were between 10 ppm and 20 ppm.

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