RESEARCH ON WATER BASED COATING CONTAINING NANO-SILICA FOR MAGNESIUM ALLOY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3629-3634 ◽  
Author(s):  
WEI HUANG ◽  
TIANLIANG ZHENG ◽  
DI LI
Keyword(s):  
Magnesium Alloy ◽  
Salt Spray ◽  
Silica Coating ◽  
Electrochemical Technique ◽  
Neutral Salt ◽  
Adhesion Test ◽  
Nano Silica ◽  
Property A ◽  
Active Chemical ◽  
Water Based

Due to magnesium's active chemical property, a novel environmental protective water based metallic coating was developed, which mainly contains metal flake, nano-silica, silicate and silane. The coating's properties were investigated by neutral salt spray test, micro-hardness testing, adhesion test and electrochemical technique etc. Meanwhile the coating surface and microstructure was observed by scanning electron microscopy (SEM). Furthermore, the effect of nano silica on the coating was also explored. Results showed that an excellent adhesive, heat-resisting, protective coating for AZ91D magnesium alloy could be achieved by this technique. It also indicated that nano silica could greatly improve the properties of coating. In the paper, mechanism of nano silica coating was also discussed.

A Novel Anti-Corrosion Coating for Aluminium Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 723-728 ◽  
Author(s):  
Wei Huang ◽  
Di Li ◽  
Tian Liang Zheng ◽  
Min Guo
Keyword(s):  
Salt Spray ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Electrochemical Technique ◽  
Neutral Salt ◽  
Test Results ◽  
Hardness Testing ◽  
Adhesion Test ◽  
Forming Mechanism ◽  
Film Forming

A novel environmental protective water based metallic coating was developed for aluminum alloys, which mainly contains metal flake, silicate and silane. The coating's properties were investigated by neutral salt spray test, micro-hardness testing, adhesion test and electrochemical technique etc. Meanwhile the coating's surface and microstructure was observed by scanning electron microscopy (SEM). Furthermore, the film forming matter was examined by Fourier transform infrared spectroscopy (FTIR) test. Results showed that an excellent adhesive, heat-resisting, protective coating for aluminum alloy could be achieved by this technique. An interpenetrating polymer network (IPN) was formed in the coating by means of cross linking reaction of organosilicone and inorganic silicate. In thesis, the film forming mechanism and protection of coating were also discussed.

scholarly journals Improvement of AZ91 Alloy Corrosion Properties by Duplex NI-P Coating Deposition

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1357 ◽  
Author(s):  
Jaromír Wasserbauer ◽  
Martin Buchtík ◽  
Jakub Tkacz ◽  
Stanislava Fintová ◽  
Jozef Minda ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Az91 Alloy ◽  
Neutral Salt ◽  
Az91 Magnesium Alloy ◽  
Corrosion Properties ◽  
Az91 Magnesium

The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.

Influence of Silane on Corrosion Performance of Silane-Modified Acrylate Interpenetrating Polymer Network Coating on Magnesium Alloy AZ31

2011 ◽  
Vol 686 ◽  
pp. 186-191
Author(s):  
Rong Chang Zeng ◽  
Chen Lan Liu ◽  
Ling Hong Kong ◽  
Hong Zhi Cui
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Salt Spray ◽  
Polymer Network ◽  
Az31 Alloy ◽  
Interpenetrating Polymer Network ◽  
Neutral Salt ◽  
Corrosion Performance ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31

The possibility that various silane treatments may enhance the corrosion resistance of a magnesium alloy AZ31 with silane-modified acrylate interpenetrating polymer network (IPN) coating has been investigated. Potentiodynamic electrochemical tests and neutral salt spray test were applied to evaluate the corrosion performance of the alloy. The results show that silane film improves corrosion resistance of the AZ31 alloy with and without IPN coating. The silane-modified IPN coatings improved more than 4 orders of magnitude of the corrosion resistance of the substrate.

Research on Water Based Coating for Magnesium Alloy

2006 ◽  
Vol 15-17 ◽  
pp. 485-490
Author(s):  
Wei Huang ◽  
Di Li ◽  
Tian Liang Zheng
Keyword(s):  
Heat Resistance ◽  
Salt Spray ◽  
Polymer Network ◽  
Chemical Properties ◽  
Hardness Test ◽  
Salt Spray Test ◽  
Interpenetrating Polymer Network ◽  
Neutral Salt ◽  
Sodium Polyphosphate ◽  
Water Based

Magnesium and its alloys have many applications for theirs excellent physical and mechanical properties. Due to magnesium’s active chemical properties and difficulties in direct painting, a novel environmental protective water based coating was developed, which mainly contains metal flake, silicate, silane and sodium polyphosphate etc. The properties and structure of the coating were investigated by adhesion test, hardness test, heat resistance test, neutral salt spray test and Scanning Electron Microscopy (SEM) et al. Meanwhile, the effect of sodium polyphosphate was also examined by hydrogen evolution test and electrochemical test. Furthermore, the film forming mechanism of the coating was explored by Fourier Transform Infrared spectroscopy (FTIR). Results showed that the coating had a stepped structure which could achieve extraordinary adhesion, 350°C temperature heat resistance, HV0.50/30 210 hardness and 300 hours anti-corrosion time in salt spray test. In the coating, the addition of sodium polyphosphate could greatly improve the corrosion resistance of the coating because of the barrier film formed by sodium polyphosphate. The mechanism of interpenetrating polymer network (IPN) was preliminary put forward based on the results of FTIR.

A Comparative Study of Zirconium-Based Coating on Cold Rolled Steel

2011 ◽  
Vol 291-294 ◽  
pp. 47-52 ◽  
Author(s):  
Shuang Hong Wang ◽  
Chang Sheng Liu ◽  
Lei Wang
Keyword(s):  
Salt Water ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Rolled Steel ◽  
Corrosion Performance ◽  
Adhesion Test ◽  
Adhesion Properties ◽  
Cold Rolled Steel ◽  
Cold Rolled

An experimental zirconium-based conversion coating on cold rolled steel was investigated in the present work. The following tests on differently pretreated panels, such as bonderite®NT-1, oxsilan®9810/1 and lz-4356, were conducted to evaluate corrosion performance include adhesion test, T-bent test, neutral salt spray test and warm salt water dipping test and electrochemical studies were also performed. The whole results showed that the experimental zirconium-based conversion coating had well-pleasing corrosion protection properties and adhesion properties, and similar lever performance as compared to the other industrial coatings. The experimental zirconium-based conversion coating was very hopeful about industrial application.

scholarly journals Design and Multidimensional Screening of Flash-PEO Coatings for Mg in Comparison to Commercial Chromium(VI) Conversion Coating

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 337
Author(s):  
Ewa Wierzbicka ◽  
Marta Mohedano ◽  
Endzhe Matykina ◽  
Raul Arrabal
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Chromium Vi ◽  
Alkaline Electrolytes ◽  
Az31b Alloy ◽  
Plasma Electrolytic

REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations demand for an expedient discovery of a Cr(VI)-free alternative corrosion protection for light alloys even though the green alternatives might never be as cheap as current harmful technologies. In the present work, flash- plasma electrolytic oxidation coatings (FPEO) with the process duration < 90 s are developed on AZ31B alloy in varied mixtures of silicate-, phosphate-, aluminate-, and fluoride-based alkaline electrolytes implementing current density and voltage limits. The overall evaluation of the coatings’ anticorrosion performance (electrochemical impedance spectroscopy (EIS), neutral salt spray test (NSST), paintability) shows that from nine optimized FPEO recipes, two (based on phosphate, fluoride, and aluminate or silicate mixtures) are found to be an adequate substitute for commercially used Cr(VI)-based conversion coating (CCC). The FPEO coatings with the best corrosion resistance consume a very low amount of energy (~1 kW h m−2 µm−1). It is also found that the lower the energy consumption of the FPEO process, the better the corrosion resistance of the resultant coating. The superb corrosion protection and a solid environmentally friendly outlook of PEO-based corrosion protection technology may facilitate the economic justification for industrial end-users of the current-consuming process as a replacement of the electroless CCC process.

scholarly journals Application of Commercial Surface Pretreatments on the Formation of Cerium Conversion Coating (CeCC) over High-Strength Aluminum Alloys 2024-T3 and 7075-T6

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 930
Author(s):  
Juan Jesús Alba-Galvín ◽  
Leandro González-Rovira ◽  
Francisco Javier Botana ◽  
Maria Lekka ◽  
Francesco Andreatta ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Salt Spray ◽  
Aluminum Matrix ◽  
Optical Emission ◽  
High Strength ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Neutral Salt ◽  
Corrosion Properties ◽  
Surface Pretreatment

The selection of appropriate surface pretreatments is one of the pending issues for the industrial application of cerium-based chemical conversion coatings (CeCC) as an alternative for toxic chromate conversion coating (CrCC). A two-step surface pretreatment based on commercial products has been successfully used here to obtain CeCC on AA2024-T3 and AA7075-T6. Specimens processed for 1 to 15 min in solutions containing CeCl3 and H2O2 have been studied by scanning electron microscopy coupled with energy-dispersive X-ray analysis (SEM-EDX), glow discharge optical emission spectroscopy (GDOES), potentiodynamic linear polarization (LP), electrochemical impedance spectroscopy (EIS), and neutral salt spray (NSS) tests. SEM-EDX showed that CeCC was firstly observed as deposits, followed by a general coverage of the surface with the formation of cracks where the coating was getting thicker. GDOES confirmed an increase of the CeCC thickness as the deposition proceed, the formation of CeCC over 7075 being faster than over 2024. There was a Ce-rich layer in both alloys and an aluminum oxide/hydroxide layer on 7075 between the upper Ce-rich layer and the aluminum matrix. According to LP and EIS, CeCC in all samples offered cathodic protection and comparable degradation in chloride-containing media. Finally, the NSS test corroborated the anti-corrosion properties of the CeCC obtained after the commercial pretreatments employed.

Influence of Nano Silica Coating on the Functional Properties of Cotton Fabrics

2009 ◽  
Vol 67 ◽  
pp. 149-154
Author(s):  
K. Sasipriya ◽  
N. Gobi ◽  
R. Palanivelu ◽  
T.V. Ramachandran ◽  
V. Rajendran
Keyword(s):  
Textile Industry ◽  
Silica Coating ◽  
Cotton Fabrics ◽  
Air Permeability ◽  
Wall Material ◽  
Nano Silica ◽  
Chemical Route ◽  
Wrinkle Resistance ◽  
Potential Applications ◽  
Nanosilica Particles

Coating of nanoparticles on fabrics provides huge potential applications in textile industry. The microencapsulation process is used to encapsulate the nanosilica particles which is used to coat on the surface of fabrics and to observe the special properties such as anti-bacterial, wrinkle resistance, etc. The amorphous nano silica particles were prepared from the natural resources through chemical route. The encapsulated nano silica was prepared using sodium alginate as a wall material by the coacervation method. The prepared sample was coated on the surface of the fabrics by pad-dry-cure method. The anti-bacterial studies were carried out for the nano silica coated and uncoated fabrics and the results would demonstrate the antibacterial effectiveness of treated cotton fabrics. The basic properties like tensile strength, tear strength, air permeability, crease recovery and whiteness index have been analysed for the coated and uncoated fabrics.

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