Research on Water Based Coating for Magnesium Alloy

2006 ◽  
Vol 15-17 ◽  
pp. 485-490
Author(s):  
Wei Huang ◽  
Di Li ◽  
Tian Liang Zheng

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.

2011 ◽  
Vol 686 ◽  
pp. 186-191
Author(s):  
Rong Chang Zeng ◽  
Chen Lan Liu ◽  
Ling Hong Kong ◽  
Hong Zhi Cui

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.


2006 ◽  
Vol 519-521 ◽  
pp. 723-728 ◽  
Author(s):  
Wei Huang ◽  
Di Li ◽  
Tian Liang Zheng ◽  
Min Guo

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.


RSC Advances ◽  
2017 ◽  
Vol 7 (25) ◽  
pp. 14981-14988
Author(s):  
Yanping Wu ◽  
Shengfa Zhu ◽  
Peng Shi ◽  
Biaojie Yan ◽  
Dingzhou Cai ◽  
...  

The corrosion behavior of Al film coated uranium and bare uranium under neutral salt spray conditions are evaluated.


Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Yuh-Chung Hu ◽  
Senthil Kumaran Selvaraj ◽  
Manivannan Subramanian ◽  
Kathiravan Srinivasan ◽  
Srinivasan Narayanan

A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 3629-3634 ◽  
Author(s):  
WEI HUANG ◽  
TIANLIANG ZHENG ◽  
DI LI

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.


2014 ◽  
Vol 1004-1005 ◽  
pp. 757-762 ◽  
Author(s):  
Shuang Hong Wang ◽  
Yong Feng Long ◽  
Shi Lu Zhao ◽  
Cheng Qiang An ◽  
Ke Ding

The water-based paint had been examined to prepare a new chromate-free insulating coating on silicon steels. The structure of the insulating coating was characterized by scanning electron microscopy, energy dispersive spectroscopy and infrared spectroscopy. Adhesion, high temperature annealing, and surface insulating resistance were measured. Corrosion resistance was investigated by neutral salt spray test and electrochemical test. Results exhibited that the insulating coating had excellent comprehensive performance. The adhesive level was 5B degree; the high temperature annealing test showed no coating degradation after heat treatment of 2 h at 450 °C in air or at 750 °C in nitrogen; the salt spray test showed the corrosion area was less than 2 % after the 12 h salt spray; when the coating thickness was 1.0-1.2 μm, the surface insulating resistance value was 380-420 Ω/mm2.


2014 ◽  
Vol 556-562 ◽  
pp. 3-5
Author(s):  
Ke Shun Dai ◽  
Wen Kai Xiao ◽  
Tan Yu

The corrosion cracking of Shielded wire could result in protection equipments and automatic devices failing to work, which seriously affects the normal operation of the grid [1]. Therefore, researching the corrosion of Shielded wire has an important meaning. This article, through measurements of the polarization curve of the shield, researched the corrosion rate of different spray time and treatments, and came to a conclusion that the corrosion resistance after passivated by 823 preservatives is higher than before it.


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