Single Dense Layer of PEO Coating on Aluminum Fabricated by “Chain-like” Discharges

Zhu, Li; Zhang, Wei; Liu, Haitao; Liu, Lei; Wang, Fuhui; Qiao, Ziping

doi:10.3390/ma15134635

Cited by 8 publications

(7 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When a capacitor is omitted from the circuit, no current can flow because, when the capacitor is charged, the current will not pass, and the circuit will be cut off. The dense oxide layer on the surface of the titanium also has this effect and, such as a capacitor after being fully charge, disrupts the electrical circuit by reducing the corrosion rate [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ]. Based on the EIS diagrams and the obtained data, it can be concluded that the corrosion resistance of the sample with plasma electrolytic oxidation coating is better than that of the uncoated sample.…”

Section: Resultsmentioning

confidence: 99%

Corrosion and Wear Behavior of TiO2/TiN Duplex Coatings on Titanium by Plasma Electrolytic Oxidation and Gas Nitriding

et al. 2022

View full text Add to dashboard Cite

In this study, corrosion and wear behavior of three kinds of coatings by two processes, namely, plasma electrolytic oxidation (PEO) coatings (Ti/TiO2), gas nitriding coating (Ti/TiN), and the duplex coating (Ti/TiO2-N) by combination of PEO and gas nitriding methods were systematically investigated. X-ray diffraction tests, field-emission scanning electron microscopy, and adhesion tests are employed for the coating characterization, along with the wear and electrochemical test for evaluating the corrosion and tribological properties. The morphology and structure of the coating consist of micro-cavities known as the pancake structure on the surface. The electrolytic plasma oxidation process produces a typical annealing behavior with a low friction coefficient based on the wear test. The coating consists of nitride and nitrate/oxides titanium for nitrided samples. The surface morphology of nitrided oxide titanium coating shows a slight change in the size of the crystals and the diameter of the cavities due to the influence of nitrogen in the titanium oxide coating. The tribological behavior of the coatings showed that the wear resistance of the duplex coating (Ti/TiO2-N) and Ti/TiO2 coatings is significantly higher compared to Ti/TiN coatings and uncoated Ti samples. The polarization resistance of the Ti/TiO2-N and Ti/TiO2 coatings was 632.2 and 1451.9 kΩ cm2, respectively. These values are considerably greater than that of the uncoated Ti (135.9 kΩ cm2). Likewise, impedance showed that the Ti/TiO2-N and Ti/TiO2 coatings demonstrate higher charge transfer resistance than that of other samples due to better insulating behavior and denser structure.

show abstract

Section: Resultsmentioning

confidence: 99%

Corrosion and Wear Behavior of TiO2/TiN Duplex Coatings on Titanium by Plasma Electrolytic Oxidation and Gas Nitriding

et al. 2022

View full text Add to dashboard Cite

show abstract

“…[56,67] These methods resulted in dense PEO coatings by controlling or reducing the discharges at the interface between the substrate and the coating. [68,69] Although such soft discharges can reduce the porous-layer-to-dense-layer ratio, achieving a single dense layer is difficult. However, Zhu et al used a novel chain-like discharge method for the PEO coating preparation on Al substrates.…”

Section: Inner Layermentioning

confidence: 99%

“…However, Zhu et al used a novel chain‐like discharge method for the PEO coating preparation on Al substrates. [ 69 ] This technique enabled the formation of a single dense layer with 2.8% porosity exhibiting high corrosion protection behaviors, good adhesion, and high hardness.…”

Section: Peo Coating Structurementioning

confidence: 99%

A Review on the Application‐Focused Assessment of Plasma Electrolytic Oxidation (PEO) Coatings Using Electrochemical Impedance Spectroscopy

Dilimon

Shibli

2023

Adv Eng Mater

View full text Add to dashboard Cite

Background of this ReviewPlasma electrolytic oxidation (PEO), micro-arc oxidation, and micro-plasma oxidation are alternative names for the same surfacecoating technology for producing multiple layers of ceramic oxides on the surface of light valve metals such as Al, Mg, Ti, Zr, Ta, Nb, Hf, and their alloys. Oxidation potentials higher than the dielectric breakdown voltage of the first formed passive film are applied through a suitable electrolyte. This high applied potential (400-600 V or higher) generates plasma discharges on the workpiece metal surface, and this plasma creates ideal conditions of high temperatures and pressures for the formation of hardened, crystalline, well-adherent, and corrosion-resistant oxide layers.The PEO process has several benefits over the conventional electrolytic oxidation process. Surface coatings formed through the PEO process have two to four times higher hardness. Their unique porous outer layer permits material scientists and engineers to customize the coating performance by incorporating different reagents, particles, and functionalities. The coating thickness can be varied from a few micrometers to more than 100 μm depending on the final target application of PEO coatings. The chemical passivity and inertness of PEO coatings enable their application in harsh environments. Reduced stiffness and crack-free edges of PEO coatings give better adhesion, making them suitable for applications under mechanical strain or thermal cycling. Also, PEO coatings technology is used for making biodegradable orthopedic implants. [1,2] PEO process with nontoxic electrolytes is an environmentally friendly technology. Qin et al. reported the preparation method of degradation resistant and in vitro cytocompatible PEO coatings on biomedical Mg alloys in green, nontoxic, and recyclable electrolytes. [3] Recent review papers describe the present status of PEO coating technology on different metals and alloys. [4][5][6][7][8][9] The last 20 years show a remarkable increase in publication numbers related to PEO coatings (Figure 1). Among them, the number of publications describing electrochemical impedance spectroscopy (EIS) for PEO coating analysis is also considerably increasing (Figure 1).The PEO coatings contain various oxides of base metals, additives, and electrolyte-borne species from the electrolyte. [10][11][12] Recent review papers describe in detail the effect of particle addition into the PEO coatings on the microstructure, composition, and corrosion behavior of coatings studied by different microscopic, spectroscopic, and electrochemical techniques. [13][14][15][16][17][18][19][20] Also, several recent research papers discuss the EIS assessment of particle-incorporated PEO coatings. [21][22][23] To a large extent, the inclusion of additives occurs in the PEO coating's outer layer, while the inner layer is mainly metal oxide of the substrate metal. [8] The size of incorporated particles in PEO coatings is in either nano or micro ranges. Recent review papers discuss the PEO coating's perfor...

show abstract

“…The combination of high micro-hardness and wear resistance with corrosion resistance ensures the wide use of products with such coatings in many industries [1][2][3]. A large number of studies has been devoted to improving the MAO process under consideration, among which one can note: imparting new properties to coatings by adding nanoparticles to the electrolyte [4][5][6], searching for new applications of MAO coatings [7,8], improving their characteristics [9][10][11][12], optimization [13][14][15][16][17][18] and control [19,20] of the oxidation process. A number of studies are devoted to the problems of identification of complex technical systems, in particular, in [21] a new algorithm for identification of a linear-time-invariant system using MATLAB is proposed.…”

Section: Introductionmentioning

confidence: 99%

Parametric identification of the mathematical model of the micro-arc oxidation process

Pecherskaya

Semenov

Golubkov

et al. 2023

Preprint

View full text Add to dashboard Cite

An electrical equivalent circuit for the micro-arc oxidation process, taking into account the resistance of the electrolyte, the resistance of the coating of the part in the form of a parallel connection of a nonlinear active resistance and reactive capacitive resistance is presented. A mathematical model describing the behavior of the electric equivalent circuit of the micro-arc oxidation process is proposed. A procedure for determining the parameters of this model, including the construction of an oscillogram of the cell resistance change and its approximation; evaluation of resistance values and capacitance of the equivalent circuit of a galvanic cell has been developed. A method for calculating the dynamic characteristics of a model of the micro-arc oxidation process is proposed. Based on the identification results, its nonlinear Simulink model is developed. The adequacy of the model is verified by comparing the calculated and experimental voltages and currents of the galvanic cell. The maximum voltage simulation error with respect to Umax does not exceed 7%, the maximum current simulation error with respect to Imax does not exceed 10%. On the basis of experimental measurements of voltages and currents using the developed method of parametric identification, the dependences of the change in model parameters on the oxidation time are obtained. It has been established that the change in the coating resistance of a part depends on the thickness of the coating being built up. The remaining parameters of the equivalent circuit in the process of micro-arc oxidation change insignificantly.

show abstract

Single Dense Layer of PEO Coating on Aluminum Fabricated by “Chain-like” Discharges

Cited by 8 publications

References 36 publications

Corrosion and Wear Behavior of TiO2/TiN Duplex Coatings on Titanium by Plasma Electrolytic Oxidation and Gas Nitriding

Corrosion and Wear Behavior of TiO2/TiN Duplex Coatings on Titanium by Plasma Electrolytic Oxidation and Gas Nitriding

A Review on the Application‐Focused Assessment of Plasma Electrolytic Oxidation (PEO) Coatings Using Electrochemical Impedance Spectroscopy

Parametric identification of the mathematical model of the micro-arc oxidation process

Contact Info

Product

Resources

About