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

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.

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

Key Engineering Materials - High-Performance Ceramics IV ◽

10.4028/0-87849-410-3.2454 ◽

2007 ◽

pp. 2454-2457

Author(s):

Hong Qi Ben ◽

Zhong Ping Yao ◽

Zhao Hua Jiang

Keyword(s):

Corrosion Resistance ◽

Ceramic Coatings ◽

Duty Ratio ◽

Plasma Oxidation

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Study of MB3 Mg Alloy by MAO Process in Different Electrolyte

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.248.54 ◽

2012 ◽

Vol 248 ◽

pp. 54-59

Author(s):

Shun Qi Zheng ◽

Xiao Jing Li ◽

Li Ping Zhu ◽

Yun Chen ◽

Jian Min Luo

Keyword(s):

Corrosion Resistance ◽

Oxidation Process ◽

Salt Spray ◽

Sample Surface ◽

Ceramic Coatings ◽

Salt Spray Test ◽

Micro Arc Oxidation ◽

Terminal Voltage ◽

Energy Disperse Spectroscopy ◽

Better Than

Micro-arc oxidation (MAO) coatings were synthesized on MB3 magnesium alloy substrate. Two different electrolyte (Ⅰ) and electrolyte (Ⅱ) were adopted, and the performance of ceramic coatings was compared. The morphology feature, phase composition, and chemical composition of the formed coatings were studied by metallographic microscope, scanning electron microscopy (SEM), energy disperse spectroscopy (EDS), XRD, respectively. The corrosion resistance of the coatings was evaluated by salt spray test. The research results show that, the starting and terminal voltage are different during the oxidation process, they are 220V and 375V in the electrolyte (Ⅰ), and 150V and 270 V in electrolyte (Ⅱ). After MAO, The sample surface in electrolyte (Ⅰ) is light gray, and looks tender and smooth. The ceramic coatings obtained in electrolyte (Ⅱ) are relative rough and white in colour. But MAO coatings obtained in electrolyte (Ⅱ) has higher deposition rate. Salt spray test show the corrosion resistance of samples obtained in electrolyte (Ⅱ) are better than those in electrolyte (Ⅰ), which is related to the thickness of the MAO coatings.

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Study on corrosion resistance and roughness of micro-plasma oxidation ceramic coatings on Ti alloy by EIS technique

Electrochimica Acta ◽

10.1016/j.electacta.2006.12.052 ◽

2007 ◽

Vol 52 (13) ◽

pp. 4539-4546 ◽

Cited By ~ 48

Author(s):

Zhongping Yao ◽

Zhaohua Jiang ◽

Fuping Wang

Keyword(s):

Corrosion Resistance ◽

Ceramic Coatings ◽

Ti Alloy ◽

Plasma Oxidation ◽

Eis Technique

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Influences of Argon Atmosphere on Ceramic Coatings on Ti–6Al–4V Alloy by Micro-Plasma Oxidation in Different Solutions

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.1717 ◽

2007 ◽

Vol 546-549 ◽

pp. 1717-1720

Author(s):

Guo Dong Hao ◽

Zhao Hua Jiang ◽

Xiao Hong Wu ◽

Yan Hua Cao

Keyword(s):

Phase Composition ◽

Ceramic Coatings ◽

Argon Atmosphere ◽

Element Content ◽

Plasma Oxidation ◽

Coating Surface ◽

Better Than

Compound ceramic coatings were prepared on Ti-6Al-4V allosy by pulsed bi-polar Micro-plasma Oxidation (MPO) in NaAlO2(S1) and Na2SiO3(S2) solution respectively. The coated samples were calcined in argon under 1000 oC. The phase composition,morphology and element content of the ceramic coatings were investigated by XRD, SEM and XRF. After oxidation in argon, The Al2TiO5 of S1 coating surface was decomposed into Al2O3. SiO2 was crystalized in S2 coating with the final proportion of SiO2 to TiO2 on the coating surface is 81:18. The morphology of the ceramic coatings after the calcination was also different. S1 coatings calcined in argon were fine, grains and pores were smaller and were combined tightly with the substrate, on the contrary, S2 coatings calcined in argon cracked on the coating surface and were separated with the substrate. The content of elements in the coatings both changed a little, which may be due to the reaction of the substrate in the oxidation. According to the phase composition and the morphology of the coatings, S1 coatings are better than S2 coatings.

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Corrosion Protection of a SiCp/ZL101 Composites by Using Plasma Electrolytic Oxidation Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1071 ◽

2009 ◽

Vol 79-82 ◽

pp. 1071-1074

Author(s):

Shi Hai Cui ◽

Hong Tao Tang ◽

Jian Yu Li ◽

Jian Min Han

Keyword(s):

Corrosion Resistance ◽

Plasma Electrolytic Oxidation ◽

Salt Spray ◽

Xrd Analysis ◽

Ceramic Coatings ◽

Immersion Test ◽

Aluminum Composites ◽

Electrolytic Oxidation ◽

Plasma Electrolytic ◽

Α Al2o3

A dense ceramic coatings with a thickness of 95μm was fabricated on a SiCp/ZL101 aluminum composites by using a plasma electrolytic oxidation(PEO) method. The XRD analysis showed that the PEO coating was mainly composed of α-Al2O3 γ-Al2O3 and mullite.The corrosion resistance of the PEO coatings and SiCp/ZL101 aluminum composites was estimated by the immersion test, salt spray test and electrochemical test. All the test results showed that the corrosion resistance of the composite was improved by the existence of the ceramic coating.

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Process and Properties of Pulse Electrodeposited RE-Ni-W-P-SiC Composite Coatings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.41-42.385 ◽

2008 ◽

Vol 41-42 ◽

pp. 385-388

Author(s):

Xiao Yun Zhu ◽

Zhong Cheng Guo

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Rare Earth ◽

Direct Current ◽

Pulse Current ◽

Composite Coatings ◽

Pulse Frequency ◽

Duty Ratio ◽

Properties Of Coatings ◽

Better Than

Process and properties of pulse electrodeposited RE-Ni-W-P-SiC composite coatings were studied. The results show that the deposited rate by pulse current is larger than that by direct current; the deposited coatings by pulse current are better than that by direct current in corrosion resistance and microhardness. And the corrosion resistance of the coatings with pulse current is better than that of stainless steel (1Cr18Ni9Ti). The duty ratio and the pulse frequency in the process of electrodeposition have a large influence on the deposition rate, the composition and the properties of coatings. SEM measurement shows that the crystals with pulse current are smaller and the surface is smoother than that by direct current. It is beneficial to make crystalline grain finer by mixing rare earth.

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