scholarly journals Influence of the parameters of the process conditions for microarc oxidation on the formation of the thickness and porosity of the oxide coating

2021 ◽  
pp. 40-43
Author(s):  
A.L. Khokhlov ◽  
◽  
D.M. Maryin ◽  
A.A. Khokhlov ◽  
◽  
...  
Keyword(s):  
Oxidation Process ◽  
Microarc Oxidation ◽  
Oxide Coating ◽  
Current Strength ◽  
Process Time ◽  
Process Conditions ◽  
Electrical Parameters ◽  
Piston Head ◽  
Micro Arc Oxidation

The process of formation of an oxide coating (strengthening and heat-insulating one) on the working surfaces of the piston head (piston bottom and grooves) using the method of micro-arc oxidation (MAO) is discussed. It is noted that during the oxidation of the piston head, the MAO process conditions will have a significant effect on the thickness and porosity of the oxide coating formed. The theoretical dependences of the influence of the electrical parameters of the microarc oxidation process conditions on the thickness and porosity of the oxide coating are presented. It has been found that the thickness of the oxidized layer will be directly proportional to the voltage and composition of the electrolyte, and the porosity is inversely proportional to the voltage and directly proportional to the current strength. It is shown that by varying the parameters of the oxidation conditions (current strength, voltage and process time), oxidized layers of the required thickness and porosity can be obtained.

scholarly journals Influence of the thickness and porosity of the oxide coating on the piston heads depending on the parameters of the microarc oxidation mode

2021 ◽  
Vol 2131 (4) ◽  
pp. 042046
Author(s):  
A Khokhlov ◽  
D Maryin ◽  
D Molochnikov ◽  
A Khokhlov ◽  
I Gayaziev ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Microarc Oxidation ◽  
Oxide Coating ◽  
Current Strength ◽  
Operating Parameters ◽  
Electrical Parameters ◽  
Piston Head

Abstract This paper discusses the process of formation of an oxide coating (hardening and heat-insulating coating) on the working surfaces of the head (top and piston grooves) of the piston by the method of microarc oxidation (MAO). In the process of oxidation of the piston head, the operating parameters of MAO will have a significant effect on the thickness and porosity of a formed oxide coating. The paper presents the theoretical relationships between the electrical parameters of the microarc oxidation mode and the thickness and porosity of the oxide coating. The thickness of the formed oxide coating on the piston heads will depend on the applied voltage and the composition of the electrolyte used. The porosity of the formed oxide coating will depend on the parameters of the current strength and the applied voltage. It is theoretically established that the formation of an oxide coating of a certain thickness and porosity occurs due to changes in the current strength, voltage and time of microarc oxidation.

scholarly journals Bitumen Production via Tar Oxidation in the Presence of Petroleum Resin with Fluorine-Containing Groups

2010 ◽  
Vol 4 (4) ◽  
pp. 325-328
Author(s):  
Michael Bratychak ◽  
◽  
Taras Chervinskyy ◽  
Olena Astakhova ◽  
Olena Shyshchak ◽  
...  
Keyword(s):  
Group Composition ◽  
Oxidation Process ◽  
Raw Material ◽  
Process Time ◽  
Process Conditions ◽  
Air Flow Rate ◽  
Structural Group ◽  
Petroleum Resin ◽  
Black Oil ◽  
Structural Group Composition

The tar oxidation process has been studied at 523 K, air flow rate of 2.0; 2.5 and 5.0 h-1 and process time of 6, 9 and 12 h in the presence of 2.5; 5.0 and 7.5 mas % (to calculate for the raw material)of petroleum resin with fluorine atoms. The tar is the residue of black oil vacuum distillation obtained from the oils of Western-Ukrainian fields. The effect of process conditions on the characteristics of obtained bitumen has been determined. The structural-group composition of blown bitumen has been examined.

scholarly journals Measurement of oxide coating thickness in the micro-arc oxidation process

2020 ◽  
Vol 1515 ◽  
pp. 042067
Author(s):  
P E Golubkov ◽  
E A Pecherskaya ◽  
T O Zinchenko ◽  
V A Baranov ◽  
G V Kozlov ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Oxidation Process ◽  
Oxide Coating ◽  
Micro Arc Oxidation

scholarly journals INFLUENCE OF ELECTRICAL PARAMETERS ON THE ROUGHNESS OF THE COATING OBTAINED IN A SHORT-PULSE MODE OF MICRO-ARC OXIDATION

2021 ◽  
pp. 29-33
Author(s):  
Pavel I. Butyagin ◽  
Keyword(s):  
Pulse Duration ◽  
Short Pulse ◽  
Pulse Repetition Frequency ◽  
Microarc Oxidation ◽  
Pulse Mode ◽  
Electrical Parameters ◽  
Wide Range ◽  
Micro Arc Oxidation ◽  
Electric Parameters ◽  
The Moment

In the course of the work it was shown that in the process of short-pulse microarc oxidation, it is possible to control electric parameters – pulse duration and pulse repetition frequency – in a wide range of 12–200 μs and 100–500 Hz, by controlling the porosity and the nature of the surface melting of the MAO coating. As a result, it becomes possible to obtain coating with the required roughness. At the maximum values of the pulse duration and frequency (200 μs and 500 Hz) at the moment of the microplasma discharge, the maximum amount of energy is released, which allows uniformly, with the smallest amount of first irregularities, to melt the coating surface, to obtain round pores of stable size. All that factors favour a decrease in the surface roughness of the MAO coating

scholarly journals Preparation and Characterization of a Sol–Gel AHEC Pore-Sealing Film Prepared on Micro Arc Oxidized AZ31 Magnesium Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 784
Author(s):  
Longlong Zhang ◽  
Yuanzhi Wu ◽  
Tian Zeng ◽  
Yu Wei ◽  
Guorui Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Sol Gel ◽  
Oxide Coating ◽  
Az31 Magnesium Alloy ◽  
Hydroxyethyl Cellulose ◽  
Gel Spinning ◽  
Test Analysis ◽  
Pore Sealing ◽  
Micro Arc Oxidation

The purpose of this study was to improve the cellular compatibility and corrosion resistance of AZ31 magnesium alloy and to prepare a biodegradable medical material. An aminated hydroxyethyl cellulose (AHEC) coating was successfully prepared on the surface of a micro-arc oxide +AZ31 magnesium alloy by sol–gel spinning. The pores of the micro-arc oxide coating were sealed. A polarization potential test analysis showed that compared to the single micro-arc oxidation coating, the coating after sealing with AHEC significantly improved the corrosion resistance of the AZ31 magnesium alloy and reduced its degradation rate in simulated body fluid (SBF). The CCK-8 method and cell morphology experiments showed that the AHEC + MAO coating prepared on the AZ31 magnesium alloy had good cytocompatibility and bioactivity.

scholarly journals Method for measuring the micro-discharges temperature in the micro-arc oxidation process

2019 ◽  
Vol 1393 ◽  
pp. 012083 ◽  
Author(s):  
P E Golubkov ◽  
E A Pecherskaya ◽  
D V Artamonov ◽  
J V Shepeleva
Keyword(s):  
Oxidation Process ◽  
Micro Arc Oxidation

Electrophysical Model of the Micro-Arc Oxidation Process

2020 ◽  
Vol 62 (11) ◽  
pp. 2137-2144 ◽  
Author(s):  
P. E. Golubkov ◽  
E. A. Pecherskaya ◽  
D. V. Artamonov ◽  
T. O. Zinchenko ◽  
Yu. E. Gerasimova ◽  
...  
Keyword(s):  
Oxidation Process ◽  
Micro Arc Oxidation

scholarly journals Zn- or Cu-Containing CaP-Based Coatings Formed by Micro-arc Oxidation on Titanium and Ti-40Nb Alloy: Part I—Microstructure, Composition and Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4116 ◽  
Author(s):  
Ekaterina G. Komarova ◽  
Yurii P. Sharkeev ◽  
Mariya B. Sedelnikova ◽  
Konstantin A. Prosolov ◽  
Igor A. Khlusov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Adhesive Strength ◽  
Applied Voltage ◽  
Oxidation Process ◽  
Pure Titanium ◽  
Atomic Ratio ◽  
Linear Increase ◽  
Microcrystalline Structure ◽  
Micro Arc Oxidation ◽  
Alloy Part

Zn- and Cu-containing CaP-based coatings, obtained by micro-arc oxidation process, were deposited on substrates made of pure titanium (Ti) and novel Ti-40Nb alloy. The microstructure, phase, and elemental composition, as well as physicochemical and mechanical properties, were examined for unmodified CaP and Zn- or Cu-containing CaP coatings, in relation to the applied voltage that was varied in the range from 200 to 350 V. The unmodified CaP coatings on both types of substrates had mainly an amorphous microstructure with a minimal content of the CaHPO4 phase for all applied voltages. The CaP coatings modified with Zn or Cu had a range from amorphous to nano- and microcrystalline structure that contained micro-sized CaHPO4 and Ca(H2PO4)2·H2O phases, as well as nano-sized β-Ca2P2O7, CaHPO4, TiO2, and Nb2O5 phases. The crystallinity of the formed coatings increased in the following order: CaP/TiNb < Zn-CaP/TiNb < Cu-CaP/TiNb < CaP/Ti < Zn-CaP/Ti < Cu-CaP/Ti. The increase in the applied voltage led to a linear increase in thickness, roughness, and porosity of all types of coatings, unlike adhesive strength that was inversely proportional to an increase in the applied voltage. The increase in the applied voltage did not affect the Zn or Cu concentration (~0.4 at%), but led to an increase in the Ca/P atomic ratio from 0.3 to 0.7.

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