Effect of Current Ratio on Plasma Electrolytic Oxide Coatings on Mg-Al Alloy

2007 ◽  
Vol 124-126 ◽  
pp. 767-770 ◽  
Author(s):  
Si Young Chang ◽  
Ye Lim Kim ◽  
Byung Heum Song ◽  
Jae Ho Lee
Keyword(s):  
Wear Resistance ◽  
Coating Layer ◽  
Ceramic Coatings ◽  
Al Alloy ◽  
Oxide Coatings ◽  
Current Ratio ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Better Than ◽  
Marked Tendency

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.

Effect of the Electrolytic Solution Composition on Properties of Ceramic Coatings on Ti Produced by PEO

2012 ◽  
Vol 174-177 ◽  
pp. 596-599
Author(s):  
Ping Yi Guo ◽  
Ning Wang ◽  
Peng Fan
Keyword(s):  
Applied Voltage ◽  
Corrosion Potential ◽  
Pure Titanium ◽  
Corrosion Current ◽  
Ceramic Coatings ◽  
Oxide Coatings ◽  
Solution Composition ◽  
Electrolytic Oxidation ◽  
State Growth ◽  
Plasma Electrolytic

Ceramic oxide coatings were produced on pure titanium by plasma electrolytic oxidation in different electrolytes. The variation of coating thickness with applied voltages revealed coating almost kept a steady-state growth rate in electrolyte A and B, but not for electrolyte C. Numerous nodules occurred on the surface of the coatings at 200V in electrolyte A and B, and then nodules disappeared with the applied voltage increasing to 300V. There was no nodules occurred, and pore size was evidently different in electrolyte C. When the applied voltage was 300V, the coating formed in electrolyte C exhibited the highest corrosion potential and lowest corrosion current density in 3.5% NaCl aqueous solution.

Mechanical and Electrochemical Properties of Plasma Electrolytic Oxide Coatings on Magnesium Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 1224-1229 ◽  
Author(s):  
Si Young Chang ◽  
Ye Lim Kim ◽  
Byung Heum Song ◽  
Jae Ho Lee
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Properties ◽  
Ceramic Coatings ◽  
Oxide Coatings ◽  
Al Content ◽  
Zn Content ◽  
Electrolytic Oxidation ◽  
Porous Microstructure ◽  
Plasma Electrolytic ◽  
Zn Alloys

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.

Influences of Current Density on Tribological Characteristics of Ceramic Coatings on 6061 Al Alloy by Plasma Electrolytic Oxidation

2011 ◽  
Vol 239-242 ◽  
pp. 1892-1895
Author(s):  
Xiao Dong Wang ◽  
Xiao Hong Wu ◽  
Rui Wang ◽  
Song Tao Lu
Keyword(s):  
Current Density ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coatings ◽  
Tribological Characteristics ◽  
Al Alloy ◽  
Friction Testing ◽  
Electrolytic Oxidation ◽  
Current Densities ◽  
Plasma Electrolytic ◽  
6061 Al Alloy

Plasma electrolytic oxidation (PEO) of an 6061 Al alloy was accomplished in an electrolyte with sodium hexametaphosphate (10 g/L) and sodium silicate (10 g/L) Coatings were produced at four different current densities (4, 6, 8 and 10 A/dm2). Phase composition, morphology and tribological characteristics of the coatings were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and ball-on-disk friction testing. The results show that among the four ceramic coatings which were produced under four current densities, the coating produced under the current density of 8 A/dm2 got the lowest wear rate with the value of 4.5 × 10-5 g/m.

scholarly journals Study of the Properties of Qxide Coatings Formed on Titanium by Plasma Electrolytic Oxidation Method

2020 ◽  
Vol 22 (1) ◽  
pp. 51
Author(s):  
Zh.M. Ramazanova ◽  
M.G. Zamalitdinova
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Plasma Electrolytic Oxidation ◽  
High Wear Resistance ◽  
Material Surface ◽  
Oxide Coatings ◽  
Uncoated Sample ◽  
Oxidation Method ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

The development of the modern industry requires to develop high-performance, environmentally friendly methods for the production of light structural material surface coatings. The use of products and structures made of titanium and its alloys with high wear resistance and corrosion resistance prevails in many industries, in particular in the aerospace industry, shipbuilding, and transport engineering. Nowadays, the application of the plasma electrolytic oxidation method, a promising metal surface treatment method, is of increasing interest. Besides this method is called microarc oxidation. The objective of this work is to study the properties of oxide coatings obtained on titanium alloys under the influence of rapid pulsed effects of the plasma electrolytic oxidation process. Oxide composite coatings were obtained in various electrolyte solutions in this work. Oxide coatings are characterized by high wear resistance. It has been established in tribological tests that the wear resistance of the coating is increased by 2–15 times compared with an uncoated sample. The friction coefficient curves obtained for coated samples show that there is no destruction of the coating to the base. The breaking-in area is marked in the curves. The friction surfaces are adjusted to each other and go to a stable friction mode. The latter results in the friction coefficient decrease and wear rate decrease.

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