Multiphase Ceramic Coatings with High Hardness and Wear Resistance on 5052 Aluminum Alloy by a Microarc Oxidation Method

2018 ◽  
Vol 6 (2) ◽  
pp. 2431-2437 ◽  
Author(s):  
Decai Qin ◽  
Guiyin Xu ◽  
Yang Yang ◽  
Song Chen
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Microarc Oxidation ◽  
High Hardness ◽  
Ceramic Coatings ◽  
Oxidation Method

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.

Corrosion tests of oxideceramic coatings formed by microarc oxidation

2020 ◽  
pp. 51-55
Author(s):  
N. S. Chernyshov ◽  
Yu. A. Kuznetsov ◽  
M. A. Markov ◽  
A. V. Krasikov ◽  
A. D. Bykova
Keyword(s):  
Corrosion Resistance ◽  
Experimental Studies ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Oxidation Method ◽  
Corrosion Tests

The results of experimental studies of the corrosion resistance of aluminum and its alloys modified with ceramic coatings based on the microarc oxidation method in some aggressive environments are presented. The mechanism of destruction of the coating is considered. Recommendations on increasing corrosion resistance are given.

Feasibility Study of AlN/Al2O3 Coating on Aluminum Alloy Using Microarc Oxidation Method

2016 ◽  
Vol 44 (12) ◽  
pp. 3148-3152
Author(s):  
Jeou-Long Lee ◽  
Kwan-Nin Kuo ◽  
Kevin Kuan-Shun Chiu ◽  
Jin-Yih Kao ◽  
Bo-Heng Lin
Keyword(s):  
Aluminum Alloy ◽  
Feasibility Study ◽  
Microarc Oxidation ◽  
Al2o3 Coating ◽  
Oxidation Method

scholarly journals The effect of electrolysis conditions during microarc oxidation on the phase-structural state, hardness and corrosion resistance of magnesium alloys

2020 ◽  
Vol 21 (3) ◽  
pp. 545-551
Author(s):  
V.V. Subbotina ◽  
V.V. Belozerov
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Magnesium Alloys ◽  
Protective Coatings ◽  
Microarc Oxidation ◽  
High Hardness ◽  
Ceramic Coatings ◽  
Functional Layer ◽  
Different Types ◽  
Spinel Mgal2o4

By the method of microarc oxidation for different types of electrolytes (which include KOH, Na2SiO3, Н2О2, NaOH, NaAlO2, Na5P3O10, NaF) and electrolysis conditions, multifunctional ceramic coatings on a magnesium alloy were obtained. The phase composition of the coating includes magnesium oxide (MgO), spinel MgAl2O4, Mg2SiO4 and Мg3(РО4)2 compounds. The phase composition of the coatings is determined by the composition of the electrolyte. The obtained MAO coatings provide high hardness, which is 1500 to 7300 MPa, as well as high corrosion resistance. The results obtained make it possible to recommend MAO coatings on magnesium alloys both as an external (functional) layer and for the formation of an underlayer for the subsequent application of protective coatings (varnishes, polymers, polytetrafluoroethylene, in particular).

Corrosion Resistance of Al2O3-ZrO2 Composite Coating by Microarc Oxidation on 2A12 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 672-675
Author(s):  
Yu Hai Li ◽  
Yan Zhao ◽  
Bao Yi Li
Keyword(s):  
Aluminum Alloy ◽  
Composite Coating ◽  
Composite Coatings ◽  
Microarc Oxidation ◽  
Composite Ceramic ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
Mixed Electrolyte ◽  
X Ray ◽  
Thickness Meter

The Al2O3-ZrO2 composite ceramic coatings were prepared on 2A12 aluminum alloy by Microarc oxidation in the mixed electrolyte of 40g/L Na2SiO3 and 8g/L Na2WO4 solution containing different ZrO2 content particles. The thickness of the coatings was measured by an eddy current thickness meter. Microstructure and phase composition were analyzed by scanning election microscopy (SEM) and X-Ray diffraction (XRD), respectively. The experimental results show that ZrO2 in electrolyte can promote coatings growth; Al2O3-ZrO2 composite ceramic coatings consist of α-Al2O3, t-ZrO2, m-ZrO2, and ZrO2 is located in island-like discharge channels and does not destroy the integrity of composite coatings; There is scarcely any erosion on the surface of Al2O3-ZrO2 composite coatings because the intermediate product Zr(OH)4 could suppress composite coating corrosion.

Steels as Materials for Sonotrode Tools

2014 ◽  
Vol 601 ◽  
pp. 21-24
Author(s):  
Jaroslav Kováčik ◽  
Štefan Emmer
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Aluminum Alloy ◽  
Tool Material ◽  
High Hardness ◽  
7075 Aluminum Alloy ◽  
Tool Steels ◽  
Ultrasound Energy ◽  
Titanium Alloy Ti6al4v ◽  
Better Than

The investigation of suitable steels for sonotrode tool applications was performed. In this case in addition to good sonotrode properties (good transmission of ultrasonic energy, resistance to gigacycle fatigue) the material ought to meet also the tool properties (high hardness and wear resistance). The study was focused on tool steels, which are relatively cheaper than the currently best sonotrode tool material FerroTitanit cermet, and better than usual sonotrode materials AW 7075 aluminum alloy and titanium alloy Ti6Al4V. The suitability of steels for this purpose was evaluated by measuring the ultrasound energy transmission at a frequency of 30 kHz.

Microarc Oxidation Coatings Fabricated on Ti3Al-Based Alloy in Silicate Electrolyte

2007 ◽  
Vol 546-549 ◽  
pp. 1769-1772 ◽  
Author(s):  
Xi Jin Li ◽  
Wen Bin Xue ◽  
Xiao Ling Wu ◽  
Guo An Cheng ◽  
Rui Ting Zheng
Keyword(s):  
Cross Section ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Dense Layer ◽  
Good Adhesion ◽  
Oxidation Method ◽  
Phase Constituent ◽  
The Cross ◽  
Loose Layer

The ceramic coatings with thickness up to 120 μm were prepared on Ti3Al-based alloy in silicate electrolyte by microarc oxidation method. The morphology, microstructure, composition and phase constituent of the coatings were investigated. Microhardness profiles along the cross-section of the coating were determined. The maximum microhardness in the coating was about 3 times higher than that of the substrate. The thickness of the coating increased with the increasing of MAO time. There were two layers in the ceramic coatings: a dense layer and a loose layer. The coating was mainly composed of (Ti0.6Al0.2Nb0.2)O2 phase. Scratching test revealed a good adhesion between the Ti3Al substrate and the coating.

Influence of the Microstructure Al-12%Si Alloy on the Properties of the Oxide Layer Formed with MAO

2016 ◽  
Vol 870 ◽  
pp. 481-486 ◽  
Author(s):  
S.K. Kiseleva ◽  
L.I. Zaynullina ◽  
N.Y. Dudareva
Keyword(s):  
Aluminum Alloy ◽  
Thermal Treatment ◽  
Microarc Oxidation ◽  
High Hardness ◽  
Matrix Solution ◽  
Initial Microstructure ◽  
The Matrix ◽  
Alloy Microstructure ◽  
Silicon Particles

The quality of coating on the high-silicon aluminum alloy Al-12%Si depending on the initial microstructure of the samples has been investigated. The method of microarc oxidation (MAO) has been used for coating. The quality of coating was evaluated by the thickness and microhardness of the formed layer. The initial microstructure of aluminum alloy samples was varied by distribution of silicon particles in the volume of the matrix solution. The possibility of obtaining a high-hardness protective coating on the alloy Al-12%Si by the MAO method has been shown. The influence of the alloy microstructure on the microhardness and thickness of coatings has been established. It has been shown that the deformation thermal treatment of Al-12%Si alloy samples before MAO leads to deterioration in the quality of the formed layer. A model of the influence of the silicon particles distribution on the quality of the micro-layer has been represented for explanation of the observed effect. The increase of microhardness in coatings with a greater thickness has been revealed.

scholarly journals Factors of quality increase in protective chromium coatings on aluminum alloys obtained through pyrolytic precipitation

2020 ◽  
Vol 2020 (10) ◽  
pp. 3-9
Author(s):  
Larisa Petrova ◽  
Victor Alexandrov ◽  
Maxim Morshchilov
Keyword(s):  
Wear Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Control Parameter ◽  
High Hardness ◽  
Coating Structure ◽  
Surface Strengthening ◽  
Kinetics Of ◽  
Aluminum Alloy Surface ◽  
Coating Growth

There are considered the problems of control parameter detection in the process of pyrolytic chromium coatings on aluminum alloy and the investigation of their impact upon coating structure, strengthening indices, adhesion strength, and also upon kinetics of coating growth. The investigations have shown that the method mentioned is promising for aluminum alloy surface strengthening, and also it allows obtaining chromium coatings with high hardness and thick constant possessing increased wear-resistance.

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