Investigation of Corrosion Resistant of Al-Zn-Si-Re-Mg Coating

2013 ◽  
Vol 652-654 ◽  
pp. 1775-1779
Author(s):  
Dong Bo Wei ◽  
Jun Huang ◽  
Ping Ze Zhang ◽  
Zheng Jun Yao ◽  
Qiang Miao ◽  
...  

A dense hot-dipping Al-Zn-Si-Re-Mg coating was prepared on the surface of steel sheet. The microstructure and toughness of coating were investigated by SEM and Nano-indentation test. The polarization curve of coating was acquired in static 3.5 wt.% NaCl solution in air at 25°C. The results show that Re and Mg improve the corrosion resistance and toughness of Al-Zn-Si coating. The formation of passive film on surface of Al-Zn-Si-Re-Mg coating is easier than that of Al-Zn-Si coating. Re decreases the number of oxygen existed in the coating. Mg3Al2(SiO4)3 depresses the porosity of coating, which is a glassy compound and formed in hot-dipping process.

2012 ◽  
Vol 727-728 ◽  
pp. 85-89
Author(s):  
Luzinete P. Barbosa ◽  
Elki C. Souza ◽  
Lucio Salgado ◽  
I. Costa

In this work, the effect of sintering atmosphere on the corrosion resistance of sintered titanium has been evaluated in 0.9 % aqueous NaCl solution to simulate physiological environment. Corrosion tests were performed on titanium porous sintered under vacuum and vacuum plus dynamic argon. The results showed better passive properties associated to the titanium sintered under argon plus vacuum atmosphere than to the vacuum sintered titanium. The better corrosion resistance of the argon plus vacuum sintered titanium was attributed to the formation of a thin passive film on the titanium surface during sintering due the low oxygen content present in this atmosphere.


2011 ◽  
Vol 299-300 ◽  
pp. 427-431
Author(s):  
Yun Li ◽  
Shi Zhi Shang ◽  
Ming Cheng ◽  
Liang Xu ◽  
Shi Hong Zhang

The corrosion behavior of Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy in 3.5% NaCl solution was investigated by using potentiodynamic polarization experiments and electrochemical impedance spectroscopy (EIS). The results show that Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy has the better corrosion resistance than its corresponding crystal alloy. During the bath in the 3.5% NaCl solution at 25°C, Zr53.5Cu26.5Ni5Al12Ag3 alloy has the lower corrosion current density than the corresponding crystal alloy. After 100h, the corrosion current densities of Zr53.5Cu26.5Ni5Al12Ag3 and the corresponding crystal alloy are 3.8415×10-8A/cm2 and 5.2827×10-7A/cm2, respectively. The results of EIS test indicate that Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy has the excellent corrosion resistance because passive film with stable structure formed on the surface in 3.5% NaCl solution. With an increase in the immersion time, the passive film becomes thicker. It leads to impedance resistance and corrosion resistance decrease. The surface of Zr53.5Cu26.5Ni5Al12Ag3 bulk amorphous alloy in 3.5% NaCl solution for 100h was analyzed by SEM and EDS. The results show that the corrosive pitting can be found at both the amorphous alloy and the corresponding crystal alloy. However, the amorphous alloy has the better corrosive pitting resistance than the crystal one because the corrosion products formed by selective dissolving of Zr and Al elements. Moreover, the addition of Ag element helps to improve the corrosion resistance of the amorphous alloy greatly.


1970 ◽  
Vol 10 ◽  
pp. 109-113 ◽  
Author(s):  
Jagadeesh Bhattarai

The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Ti alloys was studied in neutral 0.5 MNaCl solution at 25°C, open to air by immersion tests, electrochemical measurements and confocal scanning laser microscopic(CSLM) techniques. Titanium metal acts synergistically with tungsten in enhancing the corrosion resistance of the sputter-deposited W-Ti alloys so as to show higher corrosion resistance than those of alloy-constituting elements (that is, tungsten and titanium) in neutral 0.5 M NaCl solution. In particular, the amorphous W-Ti alloys containing 30-53 at% titanium showed lowest corrosion rates (that is, about 1 × 10-3 mm.y-1). Open circuit potentials of all the examined W-Ti alloys were shifted to more noble direction than those of the open circuit potentials of alloyconstituting elements in 0.5 M NaCl solution.Key words: Sputter deposition; W-Ti alloys; Corrosion-resistant; CSLM; NaCl solution.DOI: 10.3126/njst.v10i0.2899Nepal Journal of Science and Technology Volume 10, 2009 December Page:109-113 


2005 ◽  
Vol 502 ◽  
pp. 225-230 ◽  
Author(s):  
Katsuhiko Asami ◽  
H. Habazaki ◽  
Akihisa Inoue ◽  
Koji Hashimoto

Recent development of corrosion resistant bulk glassy alloys such as Zr-, Fe-, Ni- and Cu-base alloys were presented. It was clarified that the enrichment of cations in the passive film, which is responsible to corrosion resistance, depends on both alloy composition and environment. TEM observation also made it clear that alloys lose their advantageous properties such as corrosion resistance when they are devoid of or lose amorphous structure even in part due to low glass forming ability or heating. These findings were essentially similar to those of conventional amorphous alloys.


2009 ◽  
Vol 79-82 ◽  
pp. 2251-2254
Author(s):  
Xue Ting Chang ◽  
Shou Gang Chen ◽  
Yan Sheng Yin

Electrochemical impedance spectrum (EIS) and potentiodynamic polarization curve were applied to invest the corrosive behavior of Fe3Al/ZrO2 composites with different components in marine microbial medium. The results indicated that the existence of microbiology negatively moved the open circle potential. When the composites contained 30% (wt %) ZrO2, the passive film on electrodes surface was the thickest one, even after 25 days the material was still protected. When the content of ZrO2 was 90%, Fe3Al was in the least content, after 25 days the passive film has disappeared, but the material was still not eroded because of the high hardness and corrosion-resistant properties of ZrO2. When the content of ZrO2 was 80%, the passive film was partly damaged, which could lead to more serious local corrosion.


2021 ◽  
Author(s):  
Awad Sadek Mogoda ◽  
Khaled M Zohdy ◽  
Mohamed Ali Aboutabl

Abstract Corrosion of A356 Al alloy and its composites reinforced by ZrO2 and prepared by vortex and squeeze casting was studied in 3.5 % NaCl solution using poteniodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results of polarization and EIS indicated that the corrosion resistance of the vortex cast composites increases with the increasing in the vol. % of ZrO2 up to 20 % then decreases again at 30 % in the chloride solution. Also, the corrosion resistance of the squeeze cast composites increases as the squeeze pressure increases due to decreasing the porosity within these composites. Additional, the SEM micrographs well-showed that the defects and notches which appeared on the surface of the mechanically polished vortex cast composite were diminished due to growth of a protective passive film on the composite in the chloride solution. Also, the squeeze cast composite is covered by a thick passive film and less exposure to corrosion in comparing with surface of the vortex cast composite. Energy dispersive spectroscopy (EDS) spectra found out the presence of a passive aluminium oxide layer on the A356 Al alloy/ZrO2 composites.


2012 ◽  
Vol 627 ◽  
pp. 694-697 ◽  
Author(s):  
Wen Da Zhang ◽  
Jing Yang ◽  
Jing Zhi Dang ◽  
Yun Liu ◽  
Hong Xu

The hardness, compressive strength and corrosion rates of LC4 aluminum alloy in 3.5% NaCl solution before and after cryogenic treatment were measured. The microstructure, mechanical properties after cryogenic treatment and corrosion resistance of LC4 aluminum alloy were investigated. The results show that cryogenic treatment can enhance the hardness of annealed LC4 aluminum alloy. An aging treatment at 120 °C for 24 h after cryogenic treatment yielded corrosion-resistant LC4 aluminum alloy with better mechanical properties.


2008 ◽  
Vol 368-372 ◽  
pp. 1287-1290
Author(s):  
Shi Guo Du ◽  
Jun Yan ◽  
Hai Ping Cui ◽  
Bin Wang

Molybdate conversion coatings were prepared on the anodized surfaces of aluminum alloy substrates, and the corrosion resistance in 3.5% NaCl solution was also investigated. The effects of the main parameters on the quality of the coatings were discussed. The morphology and chemical composition of the conversion coatings was examined by SEM and EDS. SEM observation showed that the coatings were composed of small sheet grains with tiny cracks between them. EDS analysis showed that the main element of the coatings was molybdenum. The results of polarization curve showed that the coatings effectively inhabited the pitting corrosion of aluminum alloy substrates. In the end the possible conversion mechanism was discussed.


Sign in / Sign up

Export Citation Format

Share Document