Calcium and Phosphate Biocoatings on Magnesium Alloy Fabricated by Micro-Arc Oxidation

2010 ◽  
Vol 105-106 ◽  
pp. 565-568 ◽  
Author(s):  
Chen Ma ◽  
Xiang Yu Zhang ◽  
Li Jie Qu ◽  
Mu Qin Li
Keyword(s):  
Magnesium Alloy ◽  
Friction Coefficient ◽  
Composite Coatings ◽  
Pulse Frequency ◽  
Test Machine ◽  
Anode Polarization ◽  
Corrosion Resistant ◽  
Alloy Substrate ◽  
Phosphate Ions ◽  
Micro Arc Oxidation

Calcium phosphate biocoatings were fabricated on the surface of magnesium alloy by micro-arc oxidation (MAO) technique. The properties of biocoatings related with MAO technics parameters and the electrolyte constitute. The surface morphology, constitute and friction coefficient were studied by SEM XRD and fret test machine. The results indicated that the optimum electrolyte was CaCO3-Na3PO4 contained 20g/L phosphate ions and 1.5 Ca/P ratio, and the optimum technics parameters was 350V oxidation voltage for10min, 500HZ pulse frequency and 1:10 in duty cycle. The main phase constitutes of the porous biocoatings contained were Mg, MgO, Mg3(PO4)2 and CaNaPO4. The anode polarization potential of the coating was -1.36V and enhanced about 0.29V compared with that of magnesium alloy substrate, which indicated that the biocoatings had better corrosion resistant properties. The friction coefficient of the biocoatings was 0.23 and decreased 0.15 compared with that of magnesium alloy substrate, which indicated that the biocoatings had better wear resistant properties. The biocoatings could induce hydroxyapatite to form on its surface after soaked in body fluid, which showed that the composite coatings owned good bioactivity.

Anodic Oxidation and Silane Treatment for Corrosion Protection of AM60B Magnesium Alloy

2011 ◽  
Vol 690 ◽  
pp. 413-416 ◽  
Author(s):  
Anna da Forno ◽  
Massimiliano Bestetti ◽  
Nora Lecis ◽  
Stefano Paolo Trasatti ◽  
Monica Trueba
Keyword(s):  
Magnesium Alloy ◽  
Anodic Polarization ◽  
Oxidation Process ◽  
Composite Coatings ◽  
Silane Treatment ◽  
Nacl Solution ◽  
Corrosion Resistant ◽  
Micro Arc Oxidation ◽  
Corrosion Resistant Coatings ◽  
Scratch Tests

Oxide films have been produced on AM60B magnesium alloy using micro-arc oxidation process in an environmentally friendly alkaline solution with and without addition of different oxides nanoparticles (TiO2, ZrO2 and Al2O3). In order to seal the oxides porosity generated in the sparking process, a silane-based top coat has been applied. The surface morphology of samples was analyzed by Scanning Electron Microscopy (SEM). Scratch tests were performed for evaluating the adhesion strength of the anodic oxides. The corrosion resistance of the oxide- silane- based topcoat composite coatings was evaluated in 3.5% NaCl solution using anodic polarization tests. The anodizing in oxides nanoparticles rich solutions (ZrO2 or Al2O3), followed by a silane top coat treatment performed using OSi as precursor, is an interesting way to synthesize adherent corrosion resistant coatings on magnesium alloy AM60B.

scholarly journals The effect of pulse frequency on the electrochemical properties of micro arc oxidation coatings formed on magnesium alloy

2013 ◽  
Vol 1 (4) ◽  
pp. 318-322 ◽  
Author(s):  
Xianghua Song ◽  
Jianhong Lu ◽  
Xijiang Yin ◽  
Jianping Jiang ◽  
Jing Wang
Keyword(s):  
Magnesium Alloy ◽  
Electrochemical Properties ◽  
Pulse Frequency ◽  
Micro Arc Oxidation

Bioactivity, Wear and Corrosion Resistant Properties of Rare Earth/Calcium Phosphate Composite Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1194-1197 ◽  
Author(s):  
Chen Ma ◽  
Ying Hui Wang ◽  
Mu Qin Li ◽  
Li Jie Qu
Keyword(s):  
Rare Earth ◽  
Calcium Phosphate ◽  
Composite Coatings ◽  
Xrd Analysis ◽  
Wear Properties ◽  
Corrosion Resistant ◽  
Phosphate Coatings ◽  
Wear And Corrosion ◽  
Micro Arc Oxidation ◽  
Calcium Phosphate Coatings

Rare earth/calcium phosphate composite coatings were fabricated on the surface of Ti-6Al-4V by micro-arc oxidation (MAO) technique. The wear properties and corrosion resistant of rare earth/ calcium phosphate composite coatings in the simulated body fluid (SBF) have been investigated and the bioactivity of the composite coatings were evaluated. The results show that the friction coefficient of the composite coatings in the SBF is only 0.15~0.18 and the anode polarization potential of the coating has been obviously enhanced about 0.18V compared with that of coatings of calcium phosphate coatings. So the composite coatings have excellent wear and corrosion resistant properties. XRD analysis indicates that the composite coatings can induce hydroxyapatite to form on its surface after soaked in SBF for 9d, which shows that the composite coatings own good bioactivity.

Impedance Behavior of the Composite Coatings Prepared on Magnesium Alloy AZ91 in Simulated Seawater Solution

2014 ◽  
Vol 900 ◽  
pp. 526-530
Author(s):  
Wei Shang ◽  
Zhou Lan Yin ◽  
Yu Qing Wen ◽  
Xu Feng Wang
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Protection ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Sol Gel ◽  
Soaking Time ◽  
Magnesium Alloy Az91 ◽  
Micro Arc Oxidation ◽  
Simulated Seawater

The composite coatings were obtained on a magnesium alloy by micro-arc oxidation and sol-gel technique. Electrochemical impedance spectroscopy (EIS) was used to evaluate the corrosion behavior of MAO coating and composite coatings in a simulated seawater solution. The results show that corrosion behavior of the MAO coating and composite coatings are different at different immersion times. Corrosion protection of the MAO coating gradually weaken with the extension of soaking time, but corrosion protection of the composite coatings become stronger first and then weaken.

Enhancing Conductivity and Corrosion Resistance by Organic Coatings on AZ31 Magnesium Alloy Treated by Micro-Arc Oxidation

2019 ◽  
Author(s):  
Xiuping Zhang ◽  
Lei Li ◽  
Yaozhao Mu ◽  
Yanxiang Xie ◽  
Jun Dai ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Carbon Black ◽  
Composite Coatings ◽  
Electrochemical Corrosion ◽  
Organic Coating ◽  
Organic Coatings ◽  
Micro Arc Oxidation ◽  
Conductive Particles

Abstract In this study, an organic coating, in combination of a micro-arc oxidation ceramic layer, was prepared on the surface of a magnesium alloy (AZ31) to achieve both functions of corrosion resistance and electrical conductivity. By using carbon black as conductive particles and epoxy resin as matrix, organic coatings of various weight fractions were applied on the AZ31 surface treated by micro-arc oxidation through adjusting the contents of the conductive particles and non-conductive matrix. Electrical conductivity and corrosion resistance of organic coatings were measured. The results show that the organic coatings can improve the electrical conductivity of the AZ31 material treated by micro-arc oxidation, and the conductivity changes with the ratio between the carbon black particles and non-conductive matrix. The smallest resistance value of the organic coatings reached 130Ω. Also, the organic coating can further improve the corrosion resistance of the AZ31 material. The electrochemical corrosion tests show that the corrosion potential of the AZ31 material with composite coatings was at least 0.6V higher than that of AZ31 only with micro-arc oxidation treatment.

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