Corrosion and Wear Protection through Micro Arc Oxidation Coatings in Aluminum and Its Alloys

2019 ◽  
Author(s):  
L. Rama Krishna ◽  
G. Sundararajan
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
High Hardness ◽  
Basic Mechanism ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Wear And Corrosion Resistance ◽  
Technological Limitations

This article presents the brief overview of fairly recent and eco-friendly micro arc oxidation (MAO) coating technology. The weight-cost-performance benefits in general raised the interest to utilize lightweight materials, especially the aluminum and its alloys. Despite numerous engineering advantages, the aluminum alloys themselves do not possess suitable tribology and corrosion resistance. Therefore, improvements in surface properties are essential to enable developing potential industrial applications. For improving wear and corrosion resistance of Al alloys, the most demanding surface properties are high hardness and chemical inertness. The technical and technological limitations associated with traditional anodizing and hard anodizing processes have been the strongest driving force behind the development of new MAO technology. While presenting the key technological elements associated with the MAO process, the basic mechanism of coating formation and its phase gradient nature is presented. Influence of various process parameters including the electrolyte composition has been discussed. The typical microstructural features and distribution of α- and γ-Al2O3 phases across the coating thickness as a key strategy to form dense coatings with required mechanical, tribological, and corrosion properties which are vital to meet potential application demands are briefly illustrated.

scholarly journals Effect of Plasma Nitriding Process Conditions on Corrosion Resistance of 440B Martensitic Stainless Steel

2014 ◽  
Vol 8 (3) ◽  
pp. 156-159 ◽  
Author(s):  
Magdalena Łępicka ◽  
Małgorzata Grądzka-Dahlke
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Degradation Products ◽  
Plasma Nitriding ◽  
Electrochemical Corrosion ◽  
Industrial Applications ◽  
Process Conditions ◽  
Corrosion Properties ◽  
Dental Instruments ◽  
Increased Risk

Abstract Martensitic stainless steels are used in a large number of various industrial applications, e.g. molds for plastic injections and glass moldings, automotive components, cutting tools, surgical and dental instruments. The improvement of their tribological and corrosion properties is a problem of high interest especially in medical applications, where patient safety becomes a priority. The paper covers findings from plasma nitrided AISI 440B (PN-EN or DIN X90CrMoV18) stainless steel corrosion resistance studies. Conventionally heat treated and plasma nitrided in N2:H2 reaction gas mixture (50:50, 65:35 and 80:20, respectively) in two different temperature ranges (380 or 450°C) specimens groups were examined. Microscopic observations and electrochemical corrosion tests were performed using a variety of analytical techniques. As obtained findings show, plasma nitriding of AISI 440B stainless steel, regardless of the process temperature, results in reduction of corrosion current density. Nevertheless, applying thermo-chemical process which requires exceeding temperature of about 400°C is not recommended due to increased risk of steel sensitization to intergranular and stress corrosion. According to the results, material ion nitrided in 450°C underwent leaching corrosion processes, which led to significant disproportion in chemical composition of the corroded and corrosion-free areas. The authors suggest further research into corrosion process of plasma nitrided materials and its degradation products.

REVIEW ON IMPROVING WEAR AND CORROSION RESISTANCE OF STEELS VIA PLASMA ELECTROLYTIC SATURATION TECHNOLOGY

2016 ◽  
Vol 23 (04) ◽  
pp. 1630002 ◽  
Author(s):  
NAIMING LIN ◽  
RUIZHEN XIE ◽  
PENG ZHOU ◽  
JIAOJUAN ZOU ◽  
YONG MA ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Hardness ◽  
High Voltage Power Supply ◽  
Quenching Effect ◽  
Wear And Corrosion ◽  
The Status ◽  
Surface Performance ◽  
Steel Surfaces ◽  
Wear And Corrosion Resistance ◽  
Plasma Electrolytic

Plasma electrolytic saturation (PES) technique which holds the advantages of short treating time and limited heating influence and immediate quenching effect is conducted under high voltage power supply in some electrolyte has been extensively applied to enhance the surface performance of metallic materials. Steel is widely used in various fields thanks to its promising merits of easy workability, plasticity, toughness and weldability. It accounts for a large proportion in the application scope of the metal materials. Steel surfaces with good corrosion resistance, promising wear resistance and high hardness would be obtained by PES. Meanwhile, uniformed coatings can be formed without special requirements for substrate geometries using the PES. This paper first presents a brief introduction of the technological principle of PES. The status on studies and applications of PES for improving surface performance of steels has been reviewed.

Mechanical, tribological, and corrosion properties of composite NiP-Al2O3 with different amount of particles

2021 ◽  
pp. 1-32
Author(s):  
Renato Pessoa ◽  
Carlos A H Laurindo ◽  
Michelle S Meruvia ◽  
Ricardo D Torres ◽  
Alexandre Mikowski ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Al2o3 Particle ◽  
Corrosion Properties ◽  
Mechanical Stirring ◽  
Wear And Corrosion ◽  
Sample Orientation ◽  
Aisi 4140 ◽  
Al2o3 Particles ◽  
Wear And Corrosion Resistance ◽  
Number Of Particles

Abstract In this study, the influence of Al2O3 particle amounts on the mechanical, tribological, and corrosion properties of the composite NiP-Al2O3 coating was evaluated. AISI 4140 steel was coated with NiP through an autocatalytic bath with the addition of Al2O3 particles maintained in suspension by mechanical stirring. Following, the coated samples were annealed at 600 °C to increase the hardness and to create an interdiffusion layer, which improves coating adhesion and corrosion resistance. The coating surface was characterized by SEM/EDS, XRD, microhardness, wear resistance, and corrosion tests. The results showed that the coating particles' amount depends on the bath agitation speed, the sample orientation during the deposition, and the volume of Al2O3 particles in the bath composition. Also, the number of particles in the coating affects the deposition kinetics, the thickness of the interdiffusion layer, which affects the wear and corrosion resistance.

scholarly journals The Utilization of Carbon Dioxide to Prepare TiCxOy Films with Low Friction and High Anti-Corrosion Properties

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 533
Author(s):  
Kaixiong Gao ◽  
Zhaolong Wang ◽  
Qian Jia ◽  
Bin Zhang ◽  
Zhixing Mou ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Corrosion Resistance ◽  
Greenhouse Effect ◽  
High Hardness ◽  
Corrosion Properties ◽  
Dilute Gas ◽  
New Strategy ◽  
Co2 Recycling ◽  
Carbon Dioxide Co2 ◽  
Outstanding Question

Recycling carbon dioxide (CO2) for weakening the greenhouse effect is still an outstanding question. Although many chemical methods have been designed for CO2 conversion, they is still a need to develop new ways for CO2 recycling. Plasma methods were employed to convert CO2 into energy molecules, with the addition of H2, H2O and so on. Non heavy elements, like Ti, Cr, Si and Mo and so forth, were employed to take part in a reactive process, which might be very interesting for special scientific interest. In this work, magnetron sputtering method was used not only for igniting the plasma but also for providing Ti elements involved in reactions, via the selected Ti target. One can confirm that the TiCxOy films were successfully grew via sputtering a Ti target in CO2 atmosphere with Ar as dilute gas, which proved that CO2 is a key player in the matter of the involvement of excited CO2+, CO+, CO3− and so on, in the growth process reacting with Ti ions. The TiCxOy films exhibit the highest hardness (20.3 GPa), lowest friction coefficient (0.065) and the best corrosion resistance. The growth of the TiCxOy films are not only a new strategy for consuming CO2 but also a good way for reusing it for preparing TiCxOy films with high hardness for anti-corrosion and reducing friction. Moreover, reducing CO2 emissions via energy saving (through reducing friction and corrosion resistance) and recycling existing CO2 are both important for mitigating the greenhouse effect.

The Microstructure and Properties of CrNx Films Synthesized by Unbalanced Magnetron Sputtering

2008 ◽  
Vol 373-374 ◽  
pp. 176-179
Author(s):  
Yan Ping Wu ◽  
Yong Xiang Leng ◽  
Sun Hong ◽  
Sheng Fa Zhu ◽  
Nan Huang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Corrosion Properties ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Wear And Corrosion ◽  
Structure Thickness ◽  
Wear And Corrosion Resistance ◽  
N2 Flow Rate

CrNx film was widely used in mechanical engineering field because of its excellent anti-wear and corrosion resistance properties. While most of research was focused on mechanical properties, little attention had been paid to the corrosion resistance and residual stress of CrNx film . In this paper, CrNx films were deposited on silicon wafer (100) and iron substrate by unbalanced magnetron sputtering system (UBMS) at different N2 flow. Then the structure, thickness, residual stress, micro-hardness, wear-resistance and anti-corrosion properties of CrNx films were investigated. The results showed that the phase composition of CrNx films transformed from Cr, single phase Cr2N, Cr2N and CrN coexist to single CrN with the N2 flow rate increasing. The CrNx films composed with Cr2N phase, which deposited at 6 sccm N2 flow, had the highest microhardness and had higher compressive residual stress. Whereas the CrNx films with CrN and Cr2N phase coexist had the best wear and corrosion resistance.

scholarly journals Surface Modification of Mg0.8Ca Alloy via Wollastonite Micro-Arc Coatings: Significant Improvement in Corrosion Resistance

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 754
Author(s):  
Mariya B. Sedelnikova ◽  
Anna V. Ugodchikova ◽  
Tatiana V. Tolkacheva ◽  
Valentina V. Chebodaeva ◽  
Ivan A. Cluklhov ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Current ◽  
Biological Properties ◽  
Mineralization Process ◽  
Corrosion Properties ◽  
Oxidation Method ◽  
Significant Difference ◽  
Structure Phase ◽  
Micro Arc Oxidation ◽  
Calcium Silicates

Biodegradable materials are currently attracting the attention of scientists as materials for implants in reconstructive medicine. At the same time, ceramics based on calcium silicates are promising materials for bone recovery, because Ca2+ and Si2+ ions are necessary for the mineralization process, and they take an active part in the formation of apatite. In the presented research, the protective silicate biocoatings on a Mg0.8Ca alloy were formed by means of the micro-arc oxidation method, and the study of their morphology, structure, phase composition, corrosion, and biological properties was carried out. Elongated crystals and pores were uniformly distributed over the surface of the coatings. The coated samples exhibited remarkable anti-corrosion properties in comparison with bare magnesium alloy because their corrosion current decreased 10 times, and their corrosion resistance increased almost 100 times. The coatings did not significantly affect the viability of the cells, even without the additional dilution of the extract, and were non-toxic according to ISO 10993-5: 2009. In this case, there was a significant difference in toxicity of the pure Mg0.8Ca alloy and the coated samples. Thus, the results demonstrated that the applied coatings significantly reduced the toxicity of the alloy.

High Current Pulsed Electron Beam Effect on Micro-Arc Oxidation Film of Ti Alloy

2015 ◽  
Vol 1094 ◽  
pp. 320-324
Author(s):  
Hui Zhao ◽  
Chun Yan Du ◽  
Jin Hua Yang ◽  
Xiao Hui Wang
Keyword(s):  
Corrosion Resistance ◽  
Electron Beam ◽  
Surface Film ◽  
Anatase Phase ◽  
Porous Ceramic ◽  
Rutile Phase ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Micro Arc Oxidation ◽  
Wear And Corrosion Resistance

High Current Pulsed Electron Beam (HCPEB) was employed to treat Ti-6Al-4V alloy subjected to micro-arc oxidation. The surface morphology and phase composition of surface film were investigated, as well as the wear and corrosion resistance. The results show that the coarse porous ceramic coating becomes smooth and compact after electron beam treatment. High temperature stable rutile phase increases, and low temperature stable anatase phase reduces. The friction coefficient of composite coating reduces obviously and stabilizes at 0.2, and the wear resistance is improved. The increased corrosion potential and decreased corrosion rate exhibits an enhanced 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.

Anodizing of A356 T6 Alloys Obtained by Sub-Liquidus Casting

2008 ◽  
Vol 141-143 ◽  
pp. 755-760 ◽  
Author(s):  
Antonio Forn ◽  
Isabel Espinosa ◽  
Maite T. Baile ◽  
Elisa Rupérez
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Oxide Layer ◽  
Silicon Crystals ◽  
Wear And Corrosion ◽  
Coating Formation ◽  
Trapped Gas ◽  
Semi Solid ◽  
Wear And Corrosion Resistance ◽  
Coating Growth

Semi solid processing reduces porosity and amount of trapped gas and it allows heat treatment T6 that improves a hard anodized oxide layer. The aim of this work is to show the anodizing possibility of A356 T6 components conformed by Sub-liquidus Casting (SLC) to improve wear and corrosion resistance. This work compares the anodizing effect on tribological properties and corrosion resistance between components obtained by A6061 T6 extruded alloys and from A356 T6 produced by SLC. The effect of rounded silicon crystals on the coating formation and the fracture produced during the coating growth are described.

scholarly journals Study of the Effect of Current Pulse Frequency on Ti-6Al-4V Alloy Coating Formation by Micro Arc Oxidation

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3983 ◽  
Author(s):  
Alexander Sobolev ◽  
Alexey Kossenko ◽  
Konstantin Borodianskiy
Keyword(s):  
Corrosion Resistance ◽  
Oxide Coating ◽  
Alloy Coating ◽  
Pulse Frequency ◽  
Porous Coating ◽  
Cross Sectional ◽  
Current Frequency ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Porous Morphology

The micro arc oxidation (MAO) process has been applied to produce ceramic oxide coating on Ti-6Al-4V alloy. The MAO process was carried out at the symmetric bipolar square pulse in electrolyte containing Na2CO3 and Na2SiO3. The effect of current frequency on the surface morphology, the chemical and the phase compositions as well as the corrosion resistance was examined. Morphology and cross-sectional investigation by electron microscopy evaluated more compacted and less porous coating produced by high current frequency (1000 Hz). This alloy also exhibited a high corrosion resistance in comparison with the untreated alloy. Additionally, the alloy subjected to MAO treatment by a current frequency of 1000 Hz showed a higher corrosion resistance in comparison with alloys obtained by lower current frequencies. This behavior was attributed to more compacted and less porous morphology of the coating.

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