scholarly journals Anti-Corrosion Property of Glass Flake Reinforced Chemically Bonded Phosphate Ceramic Coatings

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2082 ◽  
Author(s):  
Ge Yan ◽  
Mingyang Wang ◽  
Tao Sun ◽  
Xinping Li ◽  
Guiming Wang ◽  
...  
Keyword(s):  
Ceramic Coating ◽  
Ceramic Materials ◽  
Crosslinking Density ◽  
Ceramic Coatings ◽  
Corrosion Property ◽  
Corrosion Mechanism ◽  
Heat Of Reaction ◽  
Curing Behavior ◽  
Bonding Phase ◽  
Glass Flake

Glass flake (GF) was used as the reinforcement in chemically bonded phosphate ceramic (CBPC) coatings to promote anti-corrosion property. The crystalline phase, curing behavior, micromorphology and electrochemical performance of the coatings were studied. The results indicate that with the addition of magnesia (MgO), a new bonding phase (Mg3(PO4)2) can be formed, which can help the CBPCs achieve a more compact and denser structure. The effect of the magnesia and the GF additives on curing behavior is obvious: the heat of reaction of the phosphate ceramic materials increases with the addition of the magnesia and the GF, which emphasizes the higher crosslinking density in the phosphate ceramic materials. The phosphate ceramic coatings with the magnesia have a higher impedance value compared with the neat phosphate ceramic coating, while the highest impedance value is obtained with increased content of GF. The corrosion mechanism is mainly contributed by the new bonding phase and GF particles, which can hinder the permeation pathway and make the permeation more circuitous.

Research on Nano-Ceramic Coatings Precision Grinding

2013 ◽  
Vol 748 ◽  
pp. 260-263
Author(s):  
Wei Xiang Liu
Keyword(s):  
Deformation Zone ◽  
Inelastic Deformation ◽  
Ceramic Coating ◽  
General Structure ◽  
Ceramic Materials ◽  
Ceramic Coatings ◽  
Precision Grinding ◽  
Microstructure Characteristics ◽  
Nanostructured Ceramic ◽  
Processing Zone

The mechanical properties and microstructure characteristics in nano-ceramic coating material determine largely their grindability, there are a variety of wear mechanisms existing in grinding process, wear resistance of nanoceramic coatings are higher than normal ceramic coating, processing zone in ceramic materials can be divided into inelastic deformation zone and elastic deformation zone. In the process of nanoceramic coatings materials removal, inelastic deformation removal and brittle removal is the coexistence, the grinding force, existing in nanostructured ceramic coatings, is bigger than it in general structure ceramic coating. In plastic deformation materials removal mode, the grinding surface roughness is low, while in brittle removal , surface grinding roughness is high , prone to grinding surface/subsurface damage.

Corrosion Resistance of Plasma Sprayed AT13 Composite Ceramic Coating on Mg

2013 ◽  
Vol 575-576 ◽  
pp. 142-146
Author(s):  
Er Lin Lu ◽  
Yan Chen ◽  
Sheng Lu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Epoxy Resin ◽  
Ceramic Coating ◽  
Composite Coatings ◽  
Composite Ceramic ◽  
Ceramic Coatings ◽  
Corrosion Property ◽  
Electrochemical Tests ◽  
Plasma Sprayed

NiCoCrAlY/AT13 composite coating was prepared by plasma spraying technology on AZ91D substrate and sealed with three different methods. The corrosion resistances of the composite ceramic coatings with and without sealing were evaluated by immersion and electrochemical tests The results show that NiCoCrAlY/AT13 composite ceramic coating represents better corrosion property than single AT13 ceramic coating. The corrosion resistances of NiCoCrAlY/AT13 composite coatings with sealing are superior to that of unsealing coating. Among three sealed coatings, both coatings sealed with paraffin and varnish exhibit better corrosion resistance with corrosion rate of 0.130 g/(m2·h), 0.204 g/(m2·h), and Icorrof 1.754E-7 (A·cm-2), 9.493E-8 (A·cm-2) respectively, while the coating with epoxy resin sealing is relatively the worst one with corrosion rate of 0.744 g/(m2·h) and Icorrof 1.650E-7 (A·cm-2).

Characterization of thermal barrier coatings formed by electon-beam physical vapor deposition (EB-PVD)

1989 ◽  
Vol 47 ◽  
pp. 426-427
Author(s):  
Ozer Unal
Keyword(s):  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
Ceramic Coating ◽  
High Vacuum ◽  
Ceramic Coatings ◽  
High Energy ◽  
Thermal Barrier ◽  
Protective Oxide ◽  
Barrier Coatings ◽  
Energy Beam

Interest in ceramics as thermal barrier coatings for hot components of turbine engines has increased rapidly over the last decade. The primary reason for this is the significant reduction in heat load and increased chemical inertness against corrosive species with the ceramic coating materials. Among other candidates, partially-stabilized zirconia is the focus of attention mainly because ot its low thermal conductivity and high thermal expansion coefficient.The coatings were made by Garrett Turbine Engine Company. Ni-base super-alloy was used as the substrate and later a bond-coating with high Al activity was formed over it. The ceramic coatings, with a thickness of about 50 μm, were formed by EB-PVD in a high-vacuum chamber by heating the target material (ZrO2-20 w/0 Y2O3) above its evaporation temperaturef >3500 °C) with a high-energy beam and condensing the resulting vapor onto a rotating heated substrate. A heat treatment in an oxidizing environment was performed later on to form a protective oxide layer to improve the adhesion between the ceramic coating and substrate. Bulk samples were studied by utilizing a Scintag diffractometer and a JEOL JXA-840 SEM; examinations of cross-sectional thin-films of the interface region were performed in a Philips CM 30 TEM operating at 300 kV and for chemical analysis a KEVEX X-ray spectrometer (EDS) was used.

Study Progress on Grinding Surface Residual Stresses for Nano-Ceramic Coatings

2013 ◽  
Vol 753-755 ◽  
pp. 277-280 ◽  
Author(s):  
Wei Xiang Liu
Keyword(s):  
Residual Stress ◽  
High Hardness ◽  
Ceramic Materials ◽  
Ceramic Coatings ◽  
Grinding Process ◽  
Monitoring And Control ◽  
Surface Residual Stress ◽  
Surface Residual Stresses ◽  
Process Monitoring And Control ◽  
Grinding Mechanism

Nano-ceramic materials had high hardness and wear resistance. Combined with current technology and cost saving, nanostructured coatings technology were carried out, using HVOF ( high velocity oxygen fuel) or plasma spraying technique can obtain high quality ceramic coating on metal substrate. Ceramic coatings produced cracks in the grinding due to grinding surface residual stress. the coatings grinding surface residual stress of engineering ceramics have been researched, grinding surface residual stress in the nanostructured ceramic coatings are being researched. the researches in this field include grinding process modeling, abrasives and grinding parameters, grinding process monitoring and control and realization of the software, the grinding mechanism and grinding damage on the surface, grinding force prediction, on-line detection, grinding on nanocoating material is a multivariable complex process.

Effect of CO2 on Anti-Corrosion Property of a Polyurea Coating Modified with Organosilicone

2014 ◽  
Vol 789 ◽  
pp. 466-470
Author(s):  
Qing Hao Shi ◽  
Bing Ying Wang ◽  
Bin Zhao
Keyword(s):  
High Temperature ◽  
Partial Pressure ◽  
Composite Coating ◽  
Corrosion Test ◽  
Electrochemical Impedance ◽  
Failure Process ◽  
Corrosion Property ◽  
Corrosion Mechanism ◽  
Partial Pressures ◽  
High Temperature High Pressure

The corrosion mechanism of organic silicon modified polyurea composite coating under different CO2 partial pressures was studied using high-temperature autoclave, combined with scanning electron microscopy (SEM), adhesion tests and electrochemical impedance spectroscopy (EIS) technology. The experimental results showed that: there was no corrosion product formed on the surface of coating sample after high-temperature high-pressure corrosion test, and with the increasing of CO2 partial pressure, the coating adhesion and impedance values decline increases. Moreover CO2 partial pressure increases accelerated the failure process of polyurea composite coating system.

Variable Parameter Processes of Micro-Arc Oxidation for Aluminium Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1273-1278
Author(s):  
Cheng Gao ◽  
Jin Yong Xu ◽  
Xuan Yi Shi ◽  
Ya Juan Liu ◽  
Jing Chun Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Wear Rate ◽  
Ceramic Coating ◽  
Early Stage ◽  
Variable Parameter ◽  
Ceramic Coatings ◽  
Constant Current ◽  
Constant Voltage ◽  
Micro Arc Oxidation ◽  
The Way

In micro-arc oxidation process, ceramic coating had a rapid growth all along by the way of constant current oxidation, and ceramic coating had a low roughness by the way of constant voltage oxidation. But few research focus on the mixed control process of constant current oxidation and constant voltage oxidation. In this paper we propose a variable parameter process that can combine the advantages of constant current and constant voltage oxidation for the first time. The growth kinetics of different technics was analyzed according to the change law of current and voltage. Surface topographs of ceramic coating were observed using scanning electron microscopy (SEM). The friction tests were carried out using a self-made friction tester. The results show that ceramic coating has an upper growth rate and a low roughness by the process of constant current+constant voltage oxidation. The ceramic coating has a high growth rate by process of constant voltage+constant current oxidation. The results of friction test indicate that the wear rate and roughness of ceramic coating are positive correlation at early stage of friction. While the ceramic coatings treated by different technics have the close wear rate at stable friction stage, which embodies the inner layer of ceramic coating has a well antiwear behavior.

Interaction of a Crack in the Plasma-Sprayed Ceramic Coating with the Metal Substrate

2005 ◽  
Vol 482 ◽  
pp. 223-226
Author(s):  
Luboš Náhlík ◽  
Zdeněk Knésl ◽  
F. Kroupa
Keyword(s):  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Surface Crack ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Metal Substrate ◽  
High Density ◽  
Initial Surface ◽  
Young’S Moduli ◽  
Plasma Sprayed

Plasma-sprayed ceramic coatings contain a high density of intrasplat microcracks which are responsible for small Young’s moduli and low fracture toughness. The extension of an initial surface crack in the direction to the interface, where the crack is repelled by the metal substrate with higher Young’s modulus, is studied using the methods of fracture mechanics. It is shown that high tensile stresses induced by the crack in the interface can lead to a local decohesion along the interface so that the crack can deviate into the interface.

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 Solid Solutions Formation Mechanism in Cordierite-Mullite Glass Materials During Ceramization

2020 ◽  
Vol 14 (4) ◽  
pp. 583-589
Author(s):  
Оksana Savvova ◽  
◽  
Hennadiy Voronov ◽  
Оlena Babich ◽  
Oleksii Fesenko ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Formation Mechanism ◽  
Glass Ceramic ◽  
High Strength ◽  
Ceramic Materials ◽  
Ceramic Coatings ◽  
Resource Saving ◽  
Aluminosilicate Glasses ◽  
Glass Ceramic Materials ◽  
Fine Crystalline Structure

Relevance of the development of high-strength glass-ceramic coatings obtained by resource-saving technology for protective elements has been established. Structure formation mechanism in magnesium aluminosilicate glasses during heat treatment has been analyzed. Selection of the system was substantiated, model glasses and glass-ceramic materials on its base have been developed. Patterns of structure regularity and formation of the phase composition of glass-ceramic materials during their ceramization have been investigated. It was established that the presence of crystalline phase of mullite after melting leads to formation of the primary crystals and allows the formation of the fine crystalline structure under conditions of the low-temperature heat treatment at the nucleation stage. Developed high-strength glass ceramic materials can be used as a base in creating protective elements for special-purpose vehicles by energy-saving technology.

Influence of Surface Microstructure of Ceramic Coatings on the Initiation and Development of Scuffing Phenomena

1998 ◽  
Author(s):  
B. Antoszewski ◽  
W. Zorawski
Keyword(s):  
Friction Force ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Surface Microstructure ◽  
Frictional Pair ◽  
Plasma Sprayed ◽  
Thermally Sprayed

Abstract This paper deals with findings of experiments concerning the scuffing phenomenon in case the frictional pair is embodying an element with a thermally sprayed ceramic coating. The progress of building up of seizure is related and evaluated for a set of ceramic coatings embodying a diversity of granulations of Al2O3TiO2 and Cr2O3 plasma sprayed on steel, the IHI8N9T steel and carbon-graphite when tested on a roller-block machine. The greatest antiscuffing resistance was recorded for Cr2O3/carbon-graphite pair. An analysis of regression approximating friction force was carried through.

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