scholarly journals Mechanical and Electrochemical Properties of Plasma Electrolytic Oxide Coatings on Aged Mg-Al alloy

2007 ◽  
Vol 17 (12) ◽  
pp. 648-653 ◽  
Author(s):  
Si-Young Chang ◽  
Ye-Lim Kim ◽  
Yang-Do Kim
2007 ◽  
Vol 124-126 ◽  
pp. 767-770 ◽  
Author(s):  
Si Young Chang ◽  
Ye Lim Kim ◽  
Byung Heum Song ◽  
Jae Ho Lee

Ceramic coatings were synthesized on pure Mg and binary Mg-7.1wt%Al alloy by plasma electrolytic oxidation (PEO) technique, and the effect of current ratio, C2/C1, ranging from 0.2 to 0.85 on their mechanical and electrochemical properties was investigated. As the C2/C1 ratio increased, the thickness of the coating layer increased, while surface roughness was almost unchanged. The hardness and wear resistance had a marked tendency to increase with increasing C2/C1 ratio and Mg-Al alloy showed higher hardness and wear resistance at all C2/C1 ratios compared to pure Mg. The weight loss of the pure Mg and Mg-Al alloy in 3.5%NaCl solution was reduced by coatings. However, it had no dependence on the C2/C1 ratio. The wear resistance of the coated Mg-Al alloy was better than that of the coated pure Mg.


2007 ◽  
Vol 539-543 ◽  
pp. 1224-1229 ◽  
Author(s):  
Si Young Chang ◽  
Ye Lim Kim ◽  
Byung Heum Song ◽  
Jae Ho Lee

Ceramic coatings were synthesized on pure magnesium, binary Mg-Al and Mg-Zn alloys by plasma electrolytic oxidation (PEO) technique, and their mechanical and electrochemical properties were investigated. The coatings showed porous microstructure and some volcano top-like pores on the surface. The coatings on Mg-Al alloys consisted of MgO, MgAl2O4 and Al2O3. In the coatings on Mg-Zn alloys, MgO and ZnO were detected. The hardness and wear resistance showed slight dependence on Al content but no tendency to increase with increasing Zn content. The coated Mg alloys with Al, Zn showed better corrosion resistance in 3.5%NaCl solution but poor corrosion resistance in methyl alcohol, compared to the coated pure Mg.


2015 ◽  
Vol 53 (8) ◽  
pp. 535-540 ◽  
Author(s):  
Young Gun Ko ◽  
Dong Hyuk Shin ◽  
Hae Woong Yang ◽  
Yeon Sung Kim ◽  
Joo Hyun Park ◽  
...  

Author(s):  
О. Halak ◽  
N. Poltorak ◽  
О. Kravchuk ◽  
V. Synko ◽  
Y. Korol

Contamination of hazardous chemicals is currently considered one of the major environmental problems. The methods of purification of gaseous emissions depending on the physicochemical properties of pollutants, in particular dangerous chemical, their aggregate state, concentration in the gas environment are studied in this article. The effect of aerosol content such as dust and soot is analyzed as well as the efficiency of purification methods at different temperature intervals, methods of purification of multicomponent mixtures. The comparative characteristics of thermochemical, reagent, sorption and catalytic methods are given and the prospects of their application in filtering systems of stationary and mobile objects are evaluated. It has been proved that almost any organic compounds can be oxidized (mineralized) on the TiO2surface. In practice, any photocatalytic air purifier includes a porous TiO2 deposited carrier, which is irradiated with ultraviolet rays and through which air is purged. Photocatalysis is suitable for domestic use as it can occur at room temperature. For example, a thermocatalytic method of destroying harmful substances requires preheating the air to a temperature above 200 ° C. Photocatalysis destroys substances that penetrate even through activated carbon filters. Features of formation of oxide coatings by plasma-electrolytic oxidation of titanium alloys are considered. It is proposed to refine the design of collective defense systems on armored vehicles and stationary facilities with additional installation in the filter-absorber of the grid with the deposited layer of catalytic material, which will neutralize various types of dangerous chemicals due to photocatalytic air purification.


2017 ◽  
Author(s):  
V. A. Borisov ◽  
S. S. Sigaeva ◽  
E. A. Anoshkina ◽  
A. L. Ivanov ◽  
P. V. Litvinov ◽  
...  

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