Effects of ceramic coating by micro-plasma oxidation on the corrosion resistance of Ti–6Al–4V alloy

2005 ◽  
Vol 200 (7) ◽  
pp. 2445-2450 ◽  
Author(s):  
Zhongping Yao ◽  
Zhaohua Jiang ◽  
Xiaohong Wu ◽  
Xuetong Sun ◽  
Zhendong Wu
Keyword(s):  
Corrosion Resistance ◽  
Ceramic Coating ◽  
Plasma Oxidation

Influences of Duty Ratio on Structure and Corrosion Resistance of Ceramic Coatings on Ti-6Al-4V by Micro-Plasma Oxidation

2007 ◽  
Vol 336-338 ◽  
pp. 2454-2457
Author(s):  
Hong Qi Ben ◽  
Zhong Ping Yao ◽  
Zhao Hua Jiang
Keyword(s):  
Corrosion Resistance ◽  
Outer Layer ◽  
Oxidation Process ◽  
Ceramic Coatings ◽  
Duty Ratio ◽  
Plasma Oxidation ◽  
Rutile Tio2 ◽  
Key Factor ◽  
Α Al2o3 ◽  
Better Than

Duty ratio is a key factor during micro-plasma oxidation process. Its influences on structure and corrosion resistance of ceramic coatings on Ti–6Al–4V by pulsed bi-polar MPO in NaAlO2 solution were investigated. The ceramic coatings were composed of Al2TiO5, α-Al2O3 and rutile TiO2, of which Al2TiO5 was the main crystalline. The coating can be divided into a porous outer layer and a dense inner layer. Compared with the condition of the same duty ratio for both pulses, the rise of anode duty ratio (D1) led to an increase in the amount of Al2TiO5 and α-Al2O3 and increased the thickness of the coating; whereas the rise of cathode duty ratio (D2) led to a decrease in the amount of α-Al2O3 and decreased the thickness of the coating. Besides, the corrosion resistance of the coated samples was better than that of Ti-6Al-4V substrate. When D1 / D2 = 60 / 30, the produced coating’s corrosion resistance was best.

scholarly journals Applying Baghdadite/PCL/Chitosan Nanocomposite Coating on AZ91 Magnesium Alloy to Improve Corrosion Behavior, Bioactivity, and Biodegradability

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 789 ◽  
Author(s):  
Farzad Soleymani ◽  
Rahmatollah Emadi ◽  
Sorour Sadeghzade ◽  
Fariborz Tavangarian
Keyword(s):  
Corrosion Resistance ◽  
Biomedical Applications ◽  
Corrosion Current Density ◽  
Ceramic Coating ◽  
Alloy Coating ◽  
Corrosion Current ◽  
Nanocomposite Coating ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

Magnesium alloys have received a great amount of attention regarding being used in biomedical applications; however, they show high degradability, poor bioactivity, and biocompatibility. To improve these properties, surface modification and various types of coatings have been applied. In this study, an anodized AZ91 alloy was coated with a polymer matrix composite made of polycaprolactone/chitosan (PCL/Ch) with different percentages of baghdadite to improve its resistance to corrosion, bioactivity, and biocompatibility. The effects of different percentages of baghdadite (0 wt %, 1 wt %, 3 wt %, and 5 wt %) on the surface microstructure, corrosion resistance, roughness, and wettability were evaluated. The results indicated that the applied nano-polymer-ceramic coating including 3 wt % baghdadite was hydrophobic, which consequently increased the corrosion resistance and decreased the corrosion current density of the anodized AZ91 alloy. Coating with 3 wt % baghdadite increased the roughness of AZ91 from 0.329 ± 0.02 to 7.026 ± 0.31 μm. After applying the polymer-ceramic coating on the surface of anodized AZ91, the corrosion products changed into calcium–phosphate compounds instead of Mg(OH)2, which is more stable in a physiological environment.

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.

Anti-Wear Coating Grown by Micro-Plasma Oxidation on Aluminum Alloys in the Solution of Aluminate-Titania

2011 ◽  
Vol 239-242 ◽  
pp. 667-670 ◽  
Author(s):  
Li Gong Zhang ◽  
Gui Mei Zhao ◽  
Xiao Ming Lai
Keyword(s):  
Aluminum Alloys ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Wear Property ◽  
Plasma Oxidation ◽  
X Ray Diffraction ◽  
Electrolytic Solution ◽  
X Ray ◽  
Hardness Tester ◽  
Wear Coating

In this paper, Aluminum trioxide ceramic coatings were grown on surfaces of 2024 Aluminum alloys by micro-plasma oxidation in an aluminate electrolytic solution. In order to decrease the density of the pores and increase the anti-wear property of the ceramic coatings, Titania were added into the aluminate electrolytic solution. The struture and anti-wear property of the produced ceramic coatings were measured by X-ray diffraction, scanning electron microscope , hardness tester and frictionometer. The results show that the thickness of the ceramic coating is about 24±1 μm, surfaces of the ceramic coatings are very uniform. The hardness of the doped coating is up to 930 HV, and the wear property of the coating is the more excellent than that of undoped coating.

The Effects of Magnetic Field on Micro-Arc Oxidation Ceramic Coating on Magnesium Alloys

2014 ◽  
Vol 960-961 ◽  
pp. 143-147
Author(s):  
Jun Zhao ◽  
Jian Jun Xi ◽  
Zhi Gang Wang ◽  
Chun Ping Zhao
Keyword(s):  
Magnetic Field ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
Friction Coefficient ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Oxidation Method ◽  
Polarization Test ◽  
Micro Arc Oxidation ◽  
Scanning Electron

Ceramic coatings were prepared on ZM5 magnetism substrate by micro-arc oxidation method with and without magnetism filed in silicate electrolyte. The morphology of the MAO coatings was investigated by scanning electron microscope (SEM). The friction coefficient of the MAO coatings prepared with magnetism is about 0.2 and more stable than the coatings prepared without magnetism. The polarization test indicated that the coating prepared with magnetism has better corrosion resistance.

Study On the Corrosion Resistance Properties of the Ceramic Coating Obtained Through Microarc Oxidation on the Aluminium Alloy Surface

2007 ◽  
Vol 353-358 ◽  
pp. 1733-1736 ◽  
Author(s):  
Fei Chen ◽  
Hai Zhou ◽  
Chen Chen ◽  
Fan Xiu Lu ◽  
Fan Xiu Lu
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Ceramic Coating ◽  
Microarc Oxidation ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Α Al2o3

Oxidation ceramic coating was directly synthesized on LY12 aluminium alloy by micro-arc oxidation (MAO) process in Na2SiO3 electrolyte solution with the Na2WO4-KOH-Na2EDTA addition. The corrosion resistance of the coating was tested using CS300P electrochemical corrosion workshop in 3.5% NaCl solution. Using the scanning electron microscopy (SEM) and X-ray diffraction (XRD), the cross-section microstructure, the surface morphology and the phase structure of the micro-arc oxidation ceramic coating were analyzed. The results showed that the corrosion resistance of the micro-arc oxidation ceramic coating in 3.5% NaCl solution was enhanced remarkably, the corrosion velocity was obviously slowed down. The thickness of micro-arc oxidation ceramic coating was about 11μm. The final phases in the coating were found to be α-Al2O3 and γ-Al2O3. The mechanism of the oxidation ceramic coating formation was investigated too.

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