Microstructure and Properties of Microarc Oxidation Ceramic Coatings on Aluminum Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 1895-1898 ◽  
Author(s):  
Wan Hui Liu ◽  
Ai Lian Bao ◽  
Xin Yu Mao ◽  
Guang Hai Zheng
Keyword(s):  
Friction And Wear ◽  
Wear Behavior ◽  
Oxide Films ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Al Alloy ◽  
Structure And Property ◽  
Al2o3 Phase ◽  
Low Wear ◽  
Α Al2o3

The paper discusses structure and property aspects of oxide films formed on 7075 aluminum alloys by microarc oxidation in alkali-silicate electrolytic solution. Microstructure, surface morphology and phase composition of the ceramic coatings were investigated by SEM and XRD. Distribution of hardness along the coating thickness was determined by microhardness analyses. The friction and wear behavior of the oxide films against steel counterparts was evaluated with a friction and wear tester. The results showed that the microarc oxidation coatings composed mainly of α-Al2O3 and γ-Al2O3 phase are dense and uniform, which indicates that the wear resistance of Al alloy could be improved obviously by microarc oxidation. The films possess a beneficial combination of 25~45 μm thickness, HV0.11500 microhardness and provide a low wear rate but a relatively high friction coefficient against GCr15 steel under dry friction condition.

Structure and Property of Micro Arc Oxidation Ceramic Coatings on Al Alloy in K2ZrF6 Solution

2010 ◽  
Vol 105-106 ◽  
pp. 505-508 ◽  
Author(s):  
Zhen Dong Wu ◽  
Zhong Wen Yao ◽  
Fang Zhou Jia ◽  
Zhao Hua Jiang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Friction And Wear ◽  
Ceramic Coatings ◽  
Al Alloy ◽  
Structure And Property ◽  
Micro Arc Oxidation ◽  
Disk Friction ◽  
Composition Structure

The coatings containing zirconia were produced on LY12 Aluminium alloy by micro-arc oxidation in K2ZrF6 and NaH2PO2 solution. The composition, structure, hardness, friction and wear resistance and corrosion resistance of the coating were studied by XRD, SEM, EDS, ball-on-disk friction tester and electrochemical analyzer, respectively. The results show that coating was composed of m-ZrO2 and t-ZrO2. There were a large amount of Zr and O and a little Al, P and K in the coating. The thickness of coating prepared for 3h was 168μm and the maximum value of the hardness was up to 16.75GPa. The friction and wear resistance and corrosion resistance were improved, compared with the LY12 aluminium alloy substrate.

scholarly journals Wear Behavior Analysis of Al2O3 Coatings Manufactured by APS and HVOF Spraying Processes Using Powder and Suspension Feedstocks

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 879
Author(s):  
Monika Michalak ◽  
Paweł Sokołowski ◽  
Mirosław Szala ◽  
Mariusz Walczak ◽  
Leszek Łatka ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Wear Behavior ◽  
Ceramic Coatings ◽  
Suspension Plasma Spraying ◽  
Atmospheric Plasma ◽  
Hvof Spraying ◽  
The Coefficient Of Friction ◽  
Wear Mode ◽  
Α Al2o3 ◽  
Plasma Sprayed

Thermally sprayed ceramic coatings are applied for the protection of surfaces that are exposed mainly to wear, high temperatures, and corrosion. In recent years, great interest has been garnered by spray processes with submicrometric and nanometric feedstock materials, due to the refinement of the structure and improved coating properties. This paper compares the microstructure and tribological properties of alumina coatings sprayed using conventional atmospheric plasma spraying (APS), and various methods that use finely grained suspension feedstocks, namely, suspension plasma spraying (SPS) and suspension high-velocity oxy-fuel spraying (S-HVOF). Furthermore, the suspension plasma-sprayed Al2O3 coatings have been deposited with radial (SPS) and axial (A-SPS) feedstock injection. The results showed that all suspension-based coatings demonstrated much better wear resistance than the powder-sprayed ones. S-HVOF and axial suspension plasma spraying (A-SPS) allowed for the deposition of the most dense and homogeneous coatings. Dense-structured coatings with low porosity (4 vol.%) and good cohesion to the metallic substrate, containing a high content of α–Al2O3 phase (56 vol.%) and a very low wear rate (0.2 ± 0.04 mm3 × 10−6/(N∙m)), were produced with the S-HVOF method. The wear mechanism of ceramic coatings included the adhesive wear mode supported by the fatigue-induced material delamination. Moreover, the presence of wear debris and tribofilm was confirmed. Finally, the coefficient of friction for the coatings was in the range between 0.44 and 0.68, with the highest values being recorded for APS sprayed coatings.

Effect of Boron-Nitrogen Containing Modified Soybean Oil Lubricating Additive on Friction and Wear Behavior of Steel-Steel and Steel-Aluminum Alloy Systems

2013 ◽  
Vol 380-384 ◽  
pp. 8-11
Author(s):  
Jian Hua Fang ◽  
Bo Shui Chen ◽  
Jiu Wang ◽  
Jiang Wu
Keyword(s):  
Aluminum Alloy ◽  
Soybean Oil ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Al Alloy ◽  
Friction And Wear Behavior ◽  
Modified Soybean Oil ◽  
Boron Nitrogen ◽  
Alloy Systems ◽  
Worn Surfaces

A type of new environmentally friendly lube additive---boron-nitrogen modified soybean oil was synthesized and characterized by infrared spectrum. Its effect on the friction and wear behavior of steel-steel and steel-aluminum alloy systems were investigated with a four-ball machine and an Optimol SRV friction and wear tester respectively. The morphographies of the worn surfaces were analyzed by means of scanning electron microscopy (SEM).The worn surfaces of the 2024Al alloy block were analyzed by means of X-ray photoelectron spectroscopy (XPS).The results show that the type of modified soybean oil as additives can obviously decrease the wear rate and friction coefficient of steel pair and steel-aluminum frictional pair. Its lubrication mechanism is inferred that a high strength adsorption film and/or tribochemistry reaction film on the worn surface of the Al alloy due the carrier effect of a long chain soybean oil, high reaction activities of nitrogen, electron-deficient of boron and their synergisms.

Tribological Performance of Ceramic Composite Coatings Obtained through Microarc Oxidation on Ly12 Aluminum Alloy

2013 ◽  
Vol 537 ◽  
pp. 7-11 ◽  
Author(s):  
Shu Hua Li ◽  
Yu Jun Yin ◽  
Da Wei Shen ◽  
Yuan Yuan Zu ◽  
Chang Zheng Qu
Keyword(s):  
Composite Coatings ◽  
Microarc Oxidation ◽  
Oxide Coating ◽  
Superficial Layer ◽  
Tribological Performance ◽  
Al Alloy ◽  
Dense Layer ◽  
X Ray Diffraction ◽  
Sand Abrasion ◽  
Α Al2o3

A dense ceramic oxide coating approximately 30µm thick was prepared on a Ly12 Al alloy by microarc oxidation in an alkali-silicate electrolytic solution. The morphology and microstructure were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD). Coating thickness and surface roughness (Ra) were measured after the coating had been synthesized. The tribological performance of the coatings was evaluated using a dry sand abrasion test and a solid particle erosion test. The results show that microarc oxidation coatings consist of the loose superficial layer and the inner dense layer. Both inner layer and out layer are composed of α-Al2O3 and γ-Al2O3, While the Al6Si2O3 phase is observed only in out loose layer. The average of the microhardness of the coating is 2096Hv.

scholarly journals Friction and wear behavior of thin-film ceramic coatings under lubricated sliding contact

2014 ◽  
Vol 569 ◽  
pp. 70-75 ◽  
Author(s):  
Cinta Lorenzo-Martin ◽  
Oyelayo O. Ajayi ◽  
Sol Torrel ◽  
Iqbal Shareef ◽  
George R. Fenske
Keyword(s):  
Thin Film ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Ceramic Coatings ◽  
Sliding Contact ◽  
Friction And Wear Behavior ◽  
Lubricated Sliding

Friction and Wear Behavior of Micro-Arc Oxidation Ceramic Coating on Pure Magnesium Surfaces

2011 ◽  
Vol 228-229 ◽  
pp. 661-665
Author(s):  
Fei Chen ◽  
Hai Zhou ◽  
Fan Xiu Lv
Keyword(s):  
Friction And Wear ◽  
Ceramic Coating ◽  
Wear Behavior ◽  
Microarc Oxidation ◽  
Pure Magnesium ◽  
Dry Sliding ◽  
Friction And Wear Behavior ◽  
Ceramic Oxide ◽  
Adhesion Wear ◽  
Micro Arc Oxidation

A relatively new process called microarc oxidation (MAO), also called plasma electrolytic oxidation (PEO), has emerged as a unique technique to produce hard, thick ceramic oxide coatings on different Mg or Al alloys. The magnesium offers various possibilities of application in industry, but its poor property in corrosion resistance, wear resistance, hardness and so on, limited its application. Through microarc oxidation, ceramic coating is directly formed on the surface of pure magnesium, by which its surface property is greatly improved. In this paper, a dense ceramic oxide ceramic coating was prepared on the magnesium by microarc oxidation in a Na2SiO3-Na2WO4-KOH-Na2EDTA electrolytic solution. The surface morphology of the coating was observed by the Scanning Electron Microscope (SEM). Using the X-ray diffraction (XRD), the phase structure of the coating was analyzed. The friction and wear behavior of the micro-arc oxidation ceramic coating under dry sliding against GCr15 steel was evaluated on a ball-on-disc test rig. The results showed that the magnesium was characterized by adhesion wear and scuffing under dry sliding against the steel, while the surface micro-arc oxidation ceramic coating experienced much abated adhesion wear and scuffing under the same testing condition. The micro-arc oxidation ceramic coating showed good friction-reducing and fair antiwear ability in dry sliding against the steel.

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.

ANTIFRICTION PROPERTY OF MICROARC OXIDATION COATING ON TITANIUM ALLOY UNDER SOLID LUBRICATING SLIDING CONDITION

2004 ◽  
Vol 11 (04n05) ◽  
pp. 367-372 ◽  
Author(s):  
Y. M. WANG ◽  
B. L. JIANG ◽  
L. X. GUO ◽  
T. Q. LEI
Keyword(s):  
Friction And Wear ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Antifriction Property ◽  
Steel Ball ◽  
Coating Surface ◽  
Ac Power ◽  
Disk Friction ◽  
Pin On Disk

Ceramic coatings were fabricated on Ti6Al4V alloy surface by microarc oxidation (MAO) in Na 2 SiO 3–( NaPO 3)6– NaAlO 2 solution using an AC power supply. Microstructure and phase composition of coating were characterized by SEM and XRD, respectively. The antifriction property of the coating with and without solid lubricant sliding against SAE 52100 steel ball was investigated on a pin-on-disk friction and wear tester. The results show that the microarc oxidation coating is relatively dense and uniform, mainly composed of rutile and anatase. The coating sliding against the steel has friction coefficient as low as 0.2–0.3 at an applied load of 0.5 N and sliding cycle below 2500, which is much smaller than that of uncoated Ti6Al4V against the same counterpart. The transferring of materials from the softer steel ball onto the coating surface is the main wear event, while the microarc oxidation coating is characterized by slight abrasive wear and adhesive wear. Introducing solid graphite lubricant into the porous surface of microarc oxidation coating significantly improves the long-term antifriction property (registering friction efficient of 0.15 in the long-term sliding) under a similar sliding condition. This improvement is attributed to the reduction of materials that are transferred from the softer steel ball onto the coating surface.

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