Changing the Sizes of Details Made of Aluminum Alloys during Microarc Oxidation Process

2021 ◽  
Vol 1037 ◽  
pp. 509-515
Author(s):  
Oleg E. Tchufistov ◽  
Evgeniy A. Tchufistov ◽  
Alexey N. Zolkin
Keyword(s):  
Aluminum Alloys ◽  
Microarc Oxidation ◽  
Liquid Solution ◽  
Ceramic Coatings ◽  
Strength Properties ◽  
Solution Temperature ◽  
Dense Ceramic ◽  
Conventional Technology ◽  
Principal Possibility

It is shown that microarc oxidation (MAO) makes it possible to increase the size of aluminum alloy details by forming dense ceramic coatings (MAO-coatings) on them. Found that MAO-process a duration of 50...80 minutes in a liquid solution according to conventional technology allows you to increase the size of the details made of deformable alloy AMg3 and D16 by 78...80 % of the thickness formed on them MAO-coating and MAO-process in solution of corundum particles opens the possibility of increasing the same details by 98...100 % of the thickness formed on them more thick MAO coating. Revealed that increasing solution temperature from 15 to 45 оС leads to a reduction in the thickness of MAO coating and an even more significant reduction in growth dimensions, as well as to reduce the quality of their surfaces. It is shown that the removal of the outer layers of MAO coatings to a thickness of 20 ... 25 μm by grinding contributes to a significant reduction in the roughness of the surfaces of details. It is confirmed that MAO coatings obtained in liquid solution and in solution with corundum particles have a similar mainly polycrystalline structure, but MAO coatings obtained in solution with corundum particles differ in greater thickness and higher corundum content (α-Al2O3). It is established that the outer layers of MAO coatings are characterized by a relatively low content of modifications of crystalline aluminum oxide, so after their removal, the strength properties of the surfaces of details also improve. The principal possibility of increasing the size of details made of deformable aluminum alloys by 150 μm with ensuring high quality of their surfaces is proved.

Effect of oxidation time on the microstructure and properties of ceramic coatings prepared by microarc oxidation on 7A04 superhard aluminum alloy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744026
Author(s):  
Feng Xiao ◽  
Hui Chen ◽  
Jingguo Miao ◽  
Juan Du
Keyword(s):  
Aluminum Alloy ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Ceramic Layer ◽  
X Ray Diffraction ◽  
Oxidation Treatment ◽  
X Ray ◽  
Metallurgical Bonding ◽  
Dense Ceramic ◽  
Morphology Of Surface

Under the sodium aluminates’ system, microarc oxidation treatment was conducted on the superhard aluminum alloy 7A04 for different times. The microstructure of microarc oxidation ceramic layer was investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influences of different oxidation times on the adhesion strength of ceramic layer and substrate, the morphology of surface and cross-section, the phase composition and the electrochemical properties were studied. The results indicated that the connection of the coating and substrate appears to be metallurgical bonding and dense ceramic layer, and the surface is in a “volcanic vent” morphology, which is composed of [Formula: see text]-Al2O3 and little [Formula: see text]-Al2O3. The corrosion resistance of ceramic layer is improved significantly in contrast with that of the substrate.

Growth of Ceramic Coatings on LY12 Aluminum Alloys by Micro-Arc Oxidation and Microstructure Properties of Ceramic Coatings

2012 ◽  
Vol 508 ◽  
pp. 246-249 ◽  
Author(s):  
Jing Long Gao ◽  
Zhong Cai Shao ◽  
Tong Zhen Li
Keyword(s):  
Aluminum Alloys ◽  
Treatment Time ◽  
Microarc Oxidation ◽  
Cell Voltage ◽  
Sodium Metasilicate ◽  
Ceramic Coatings ◽  
High Rate ◽  
Micro Arc Oxidation ◽  
Al2o3 Phase ◽  
Two Stages

LY12 aluminum alloy samples were treated by microarc oxidation in sodium metasilicate electrolytes. The effects of treatment time on cell violate and ceramic coating thickness were investigated. The results indicate that the micro-arc oxidization process was divided into two stages, at the first stage, the cell voltage increased linearly at a very high rate of 70 V/min, at the second stage, in the range of 430-470 V, the cell voltage reached a relative stable value. The thickness of the coating increased linearly at the whole stage with increasing treating time. XRD analyses indicate that the ceramic coatings fabricated on the surface of aluminum alloys by micro-arc oxidization are composed of Al phase Al2O3 phase. SEM show that the maximum porosity of the ceramic coatings with distributing uniformly pore diameter are decreased with the increasing treatment time.

PREPARATION OF MICROARC OXIDATION COATINGS ON 6061 ALUMINUM ALLOYS AND THEIR THERMAL SHOCK RESISTANCE

2009 ◽  
Vol 16 (03) ◽  
pp. 393-399 ◽  
Author(s):  
WENBIN XUE ◽  
YING ZHANG ◽  
XINGLI JIANG ◽  
ZHUO YANG
Keyword(s):  
Aluminum Alloys ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Microarc Oxidation ◽  
Alloy Coating ◽  
Ceramic Coatings ◽  
Phase Constituent ◽  
Thick Coating ◽  
Coated Alloy ◽  
Shock Resistance

The thick ceramic coatings were prepared on 6061 aluminum alloys by microarc oxidation in a silicate electrolyte. The morphology and phase constituent of the coatings with different thickness were studied by scanning electron microscope, and X-ray diffraction. Scratch and thermal shock tests were employed to evaluate the adhesion between the coating and alloy substrate. The maximum microhardness and its position away from alloy/coating interface increases with increasing the coating thickness. The critical scratch force for the coating break was about 55 N in the 50 μm thick coating. Thermal shock resistance of the coatings depend on their thickness and thinner coating has better thermal shock resistance. The coated alloy with 50 μm thick coating can be subjected to 50 times thermal cycles of heating up to 500°C followed by quenching into water.

scholarly journals Piezoelectric Thick Film Deposition via Powder/Granule Spray in Vacuum: A Review

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 59
Author(s):  
Deepak Rajaram Patil ◽  
Venkateswarlu Annapureddy ◽  
J. Kaarthik ◽  
Atul Thakre ◽  
Jun Akedo ◽  
...  
Keyword(s):  
Thick Film ◽  
Thick Films ◽  
Cost Effective ◽  
Aerosol Deposition ◽  
Ceramic Coatings ◽  
Film Deposition ◽  
Energy Harvesters ◽  
Ceramic Films ◽  
Dense Ceramic ◽  
Processing Techniques

Conventional thin-film processing techniques remain inadequate for obtaining superior dense ceramic thick films. The incompatibility of ceramic films prepared via other methods, such as screen printing, spin coating, and sputtering, is a major obstacle in the fabrication of thick film-based ceramic electronic components. The granule spray in vacuum (GSV) processes and aerosol deposition (AD) are important coating approaches for forming dense ceramic thick films featuring nanoscale crystallite structures at room temperature, which offer excellent material properties and facilitate cost-effective production. AD ceramic coatings require the acceleration of solid-state submicron ceramic particles via gas streams with a velocity of a few hundred meters per second, which are then wedged onto a substrate. This process is economical and particularly useful for the fabrication of piezoelectric thick film-based microactuators, energy harvesters, sensors, and optoelectronic devices. More recently, the GSV technique was improved to achieve more uniform and homogeneous film deposition after AD. This review article presents a detailed overview of the AD and GSV processes for piezoelectric thick films in terms of recent scientific and technological applications.

Influence of Agglomerate Size on the Properties of Al2O3-Al2Cu3 Multiphase Ceramic Coatings

2007 ◽  
Vol 336-338 ◽  
pp. 1791-1792
Author(s):  
Hai Ping Cui ◽  
Jun Yan ◽  
Shi Guo Du ◽  
Xin Kang Du
Keyword(s):  
Mechanical Properties ◽  
Size Range ◽  
Ceramic Coatings ◽  
Reactive System ◽  
Flame Spray ◽  
Agglomerate Size ◽  
Binding Strength

Al2O3-Al2Cu3 multiphase coatings were prepared on the surface of steel by reactive flame spray. The binding strength, microhardness and abrasion quality of the coatings were measured and analyzed. The influence of the agglomerate size on the properties of the coatings was emphatically studied to choose suitable size range for Al-CuO reactive system. The results showed that coatings prepared by using –150∼+250 meshes agglomerates exhibited good mechanical properties.

Effects of additives in electrolyte on characteristics of ceramic coatings formed by microarc oxidation

1999 ◽  
Vol 15 (2) ◽  
pp. 109-111 ◽  
Author(s):  
Y.K. Wang ◽  
L. Sheng ◽  
R.Z. Xiong ◽  
B.S. Li
Keyword(s):  
Microarc Oxidation ◽  
Ceramic Coatings

Weldability: Effect of Alloying Element Sc, Mn, and Zr on Alloys of the Al-Mg-Sc-Mn-Zr System

2019 ◽  
Author(s):  
V. I. Lukin
Keyword(s):  
Aluminum Alloys ◽  
Practical Importance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Mg Alloy ◽  
Alloying Element ◽  
Processing Properties ◽  
Alloys Of The Al ◽  
Effect Of Alloying

Scandium in aluminum alloys behaves as the most efficient modifier of the structure of the material and as an agent suppressing recrystallization. This unique behavior of scandium in alloys of the Al-Mg system greatly increases the strength characteristics, whilst retaining on a higher level the ductility and processing properties of deformed semi-finished products. This article describes the effect of complex alloying the Al-6.3% Mg alloy with scandium, manganese and zirconium on the weldability and strength properties of the material is of considerable scientific and practical importance.Investigations.

scholarly journals Effect of Anodic Current Density on Characteristics and Low Temperature IR Emissivity of Ceramic Coating on Aluminium 6061 Alloy Prepared by Microarc Oxidation

2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Mohannad M. S. Al Bosta ◽  
Keng-Jeng Ma ◽  
Hsi-Hsin Chien
Keyword(s):  
Surface Roughness ◽  
Current Density ◽  
Ceramic Coating ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Anodic Current Density ◽  
Ceramic Surface ◽  
Anodic Current ◽  
Alumina Phase ◽  
Current Densities

High emitter MAO ceramic coatings were fabricated on the Al 6061 alloy, using different bipolar anodic current densities, in an alkali silicate electrolyte. We found that, as the current density increased from 10.94 A/dm2 to 43.75 A/dm2, the layer thickness was increased from 10.9 μm to 18.5 μm, the surface roughness was increased from 0.79 μm to 1.27 μm, the area ratio of volcano-like microstructure was increased from 55.6% to 59.6%, the volcano-like density was decreased from 2620 mm−2 to 1420 mm−2, and the γ-alumina phase was decreased from 66.6 wt.% to 26.2 wt.%, while the α-alumina phase was increased from 3.9 wt.% to 27.6 wt.%. The sillimanite and cristobalite phases were around 20 wt.% and 9 wt.%, respectively, for 10.94 A/dm2 and approximately constant around 40 wt.% and less than 5 wt.%, respectively, for the anodic current densities 14.58, 21.88, and 43.75 A/dm2. The ceramic surface roughness and thickness slightly enhanced the IR emissivity in the semitransparent region (4.0–7.8 μm), while the existing phases contributed together to raise the emissivity in the opaque region (8.6–16.0 μm) to higher but approximately the same emissivities.

scholarly journals Method of applying protective and electrical insulating ceramic coatings by microarc oxidation under overpressure conditions

2019 ◽  
Vol 1 (5) ◽  
pp. 109-111
Author(s):  
M. A. Markov ◽  
B. V. Farmakovsky ◽  
A. V. Krasikov ◽  
A. D. Bykova ◽  
S. N. Perevislov ◽  
...  
Keyword(s):  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Electrolytic Deposition

The results of the development of the technology of electrolytic deposition of protective and electrical insulating ceramic coatings are presented. The developed technology consists in the combination of microarc oxidation with the imposition of overpressure in a closed autoclave with the introduction of nanoparticles into the probe of the formation of coatings.

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