Microarc oxidation ‐ A promising method of producing ceramic coatings

Karakozov, E. S.; Chavdarov, Anatoliy V.; Barykin, N V

doi:10.1080/09507119409548577

Cited by 5 publications

(2 citation statements)

References 2 publications

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“…Wei et al [7] mentioned that the smaller the interelectrode distance the better the corrosion resistance of the coating; moreover, they have found that current pulses reached maximum amplitude on the nearer parts of substrate earlier than on the farther ones. The importance of the interelectrode distance in PEO under galvanostatic conditions was also reported in [8,9]. The extension of this technique is the so-called 'scanning micro arc oxidation', wherein a small-area counter electrode is moved through the surface of a larger substrate, allowing uniform coatings to be produced on the large and complex substrates [10,11].…”

Section: Introductionmentioning

confidence: 90%

The role of cathodic current in plasma electrolytic oxidation of aluminium: current density ‘scanning waves’ on complex-shape substrates

Rogov¹,

Yerokhin²,

Matthews³

2018

J. Phys. D: Appl. Phys.

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This paper focuses on the factors that influence the surface distribution of the current density during plasma electrolytic oxidation of 2024 Al alloy under alternating polarisation. It was found that employing the combined current mode, including relatively long (100–2000 ms) pulse trains, improved coating uniformity even when the electrolyser provided a severe nonuniform primary electric field. An experimental investigation employing a sectioned sample showed that the nonuniform distribution of the primary electric field could be compensated by the changes in the coating properties induced by previous cathodic polarisation. Temporary changes in the secondary distribution of current density across the sample surface (attributed to the coating properties) caused dynamic redistribution of the anodic current density during the following AC pulse train, resulting in the so-called ‘scanning wave’ effect, i.e. migration of the maximum current density along the sample surface. Factorial experimental design, finite element modelling and analysis of the transient current–voltage curves were applied. A mechanistic explanation underlying the considered phenomenon has been suggested. In addition, the increase in plasma electrolytic oxidation efficiency under soft sparking conditions is considered as ‘electrocatalysis’ of anodic oxidation by previous cathodic treatment.

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Section: Introductionmentioning

confidence: 90%

The role of cathodic current in plasma electrolytic oxidation of aluminium: current density ‘scanning waves’ on complex-shape substrates

Rogov¹,

Yerokhin²,

Matthews³

2018

J. Phys. D: Appl. Phys.

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“…Micro-arc oxidation (MAO), also known as plasma electrolytic oxidation, was first proposed by Markov and co-workers (Markov and Markova, 1976). MAO has emerged as a novel and unique technique for generating thick, dense, and ultra-hard ceramic coatings on aluminium alloys (Karakozov et al, 1994). These MAO coatings were reported to have excellent wear, friction, corrosion, electrical, and thermal properties, which are of particular importance to aerospace components, textile machine components, engineering equipment components, and biomedical devices.…”

Section: Introductionmentioning

confidence: 99%

Application of MAO‐processed ceramic layer in micro thrusters

Kang

Xin²,

Jin³

et al. 2011

Aircraft Engineering and Aerospace Technology

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Purpose -The purpose of this paper is to propose and assess the possibility of using ceramic coating layer as a heat-resistant material in micro solid propellant thruster. Design/methodology/approach -A ceramic layer is coated on the inner surface of the combustor of a micro thruster by applying micro-arc oxidation (MAO) technology. The thermal property of the coating is analyzed with laser pulse method. To evaluate the heat-resistant performance of the coating, the temperature history of the micro thruster inner surface is experimentally tested and recorded in a water thermostat bath. A numerical simulation of the thruster working condition is also carried out. Findings -Both experimental and simulation results reveal that the heat-resistant ability of the coating processed by MAO is proven to be effective. Practical implications -This paper attempts to help designers choose material processing technology to improve micro solid propellant thruster heatresistant ability. Originality/value -The paper shows that with a ceramic coating layer processed with MAO, aluminium can sustain higher temperature and it can be used as the structural material for short-time-work micro thruster.

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