Preparation of ceramic coating on Ti substrate by plasma electrolytic oxidation in different electrolytes and evaluation of its corrosion resistance: Part II

2012 ◽  
Vol 258 (7) ◽  
pp. 2416-2423 ◽  
Author(s):  
M. Shokouhfar ◽  
C. Dehghanian ◽  
M. Montazeri ◽  
A. Baradaran
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

scholarly journals Fabrication and Characterization of Ceramic Coating on Al7075 Alloy by Plasma Electrolytic Oxidation in Molten Salt

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 993
Author(s):  
Alexander Sobolev ◽  
Tamar Peretz ◽  
Konstantin Borodianskiy
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrochemical Impedance ◽  
Current Frequency ◽  
Electrolytic Oxidation ◽  
Fabrication And Characterization ◽  
Plasma Electrolytic

The fabrication of a ceramic coating on the metallic substrate is usually applied to achieve the improved performance of the material. Plasma electrolytic oxidation (PEO) is one of the most promising methods to reach this performance, mostly wear and corrosion resistance. Traditional PEO is carried out in an aqueous electrolyte. However, the current work showed the fabrication and characterization of a ceramic coating using PEO in molten salt which was used to avoid disadvantages in system heating-up and the formation of undesired elements in the coating. Aluminum 7075 alloy was subjected to the surface treatment using PEO in molten nitrate salt. Various current frequencies were applied in the process. Coating investigations revealed its surface porous structure and the presence of two oxide layers, α-Al2O3 and γ-Al2O3. Microhardness measurements and chemical and phase examinations confirmed these results. Potentiodynamic polarization tests and electrochemical impedance spectroscopy revealed the greater corrosion resistance for the coated alloy. Moreover, the corrosion resistance was increased with the current frequency of the PEO process.

In Situ Formation of ZrO2-Y2O3-Containing Ceramic Coating on Magnesium Alloy by Plasma Electrolytic Oxidation

2011 ◽  
Vol 295-297 ◽  
pp. 1684-1690
Author(s):  
Hai He Luo ◽  
Qi Zhou Cai
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrochemical Corrosion ◽  
Dense Layer ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

A ZrO2-Y2O3-containing composite ceramic coating was firstly in situ prepared on AZ91D magnesium alloy by plasma electrolytic oxidation (PEO) technique in an alkaline silicate-containing electrolyte. The morphology, chemical composition and corrosion resistance of the PEO coating were investigated by environmental scanning electron microscopy (ESEM), X-ray diffractometer (XRD), energy dispersive X-ray (EDX) spectrometer, dropping corrosion and electrochemical corrosion test. The results showed that the ceramic coating consisted of two distinct structural layers: an outer loose layer and an inner dense layer; it was composed of t-ZrO2, Y2O3, SiO2and some magnesium compounds, such as MgO,MgF2and Mg2SiO4. In addition, the ceramic coating also showed excellent dropping and electrochemical corrosion resistance, which was mainly attributed to its special phase composition and microstructure.

Enhancement of Corrosion Resistance of PEO Coating on AZ91 Biomedical Magnesium Alloy by Surface Laser Treating

2013 ◽  
Vol 365-366 ◽  
pp. 1110-1113 ◽  
Author(s):  
Miao Wang ◽  
Yun Long Wang ◽  
Zhong De Liu ◽  
Hua Ding
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Alloy Sample ◽  
Corrosion Tests ◽  
Coating Surface ◽  
Electrolytic Oxidation ◽  
Surface Laser ◽  
Plasma Electrolytic

Ceramic coating was fabricated on AZ91 biomedical magnesium alloy by plasma electrolytic oxidation. The coating was then subjected to surface laser treating, and the influence of laser treating on the morphologies and corrosion resistance of the coating were investigated. The results showed that PEO coating without laser treating showed coarse and porous surface and the pores on coating surface were big. When subjected to laser treating, the pores on coating surface became little and few. The corrosion tests in SBF indicated that corrosion resistance of PEO coating on magnesium alloy sample could improve the corrosion resistance of the substrate, and surface laser treating could further increase the corrosion resistance.

Fabrication of Al2O3 Ceramic Coating on AZ91 Biomedical Magnesium Alloy and the Corrosion Resistance in SBF

2013 ◽  
Vol 365-366 ◽  
pp. 1114-1117
Author(s):  
Yun Long Wang ◽  
Shuo Wang ◽  
Miao Wang ◽  
Li Jie Shi ◽  
Hui Rong Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Coated Sample ◽  
Uncoated Sample ◽  
Electrolytic Oxidation ◽  
Simulated Body Fluids ◽  
Plasma Electrolytic

Al2O3ceramic coating was fabricated on AZ91 biomedical magnesium alloy by plasma electrolytic oxidation. The microstructure of the coatings was characterized. The corrosion behavior of the coated magnesium alloy in simulated body fluids (SBF) was evaluated. The results showed that the as prepared coating was composed of crystal Al2O3, including much α-Al2O3and some γ-Al2O3. The Al2O3.coating showed porous surface and the biggest diameters of the holes were about 6-7 um, and the smallest were about 1 um. The corrosion tests in SBF indicated that corrosion resistance of Al2O3coated sample was significantly improved compared to the uncoated sample.

scholarly journals Surface Modification of Aluminum 6061-O Alloy by Plasma Electrolytic Oxidation to Improve Corrosion Resistance Properties

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Dmitry V. Dzhurinskiy ◽  
Stanislav S. Dautov ◽  
Petr G. Shornikov ◽  
Iskander Sh. Akhatov
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
High Strength ◽  
Electrolytic Oxidation ◽  
Coating Layers ◽  
Plasma Electrolytic ◽  
High Strength Aluminum Alloys

In the present investigation, the plasma electrolytic oxidation (PEO) process was employed to form aluminum oxide coating layers to enhance corrosion resistance properties of high-strength aluminum alloys. The formed protective coating layers were examined by means of scanning electron microscopy (SEM) and characterized by several electrochemical techniques, including open circuit potential (OCP), linear potentiodynamic polarization (LP) and electrochemical impedance spectroscopy (EIS). The results were reported in comparison with the bare 6061-O aluminum alloy to determine the corrosion performance of the coated 6061-O alloy. The PEO-treated aluminum alloy showed substantially higher corrosion resistance in comparison with the untreated substrate material. A relationship was found between the coating formation stage, process parameters and the thickness of the oxide-formed layers, which has a measurable influence on enhancing corrosion resistance properties. This study demonstrates promising results of utilizing PEO process to enhance corrosion resistance properties of high-strength aluminum alloys and could be recommended as a method used in industrial applications.

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