The Weibull Distribution of Microhardness in Plasma Sprayed NiCrAl/AT13 Nanostructured Ceramic Coating

2013 ◽  
Vol 321-324 ◽  
pp. 318-323
Author(s):  
Gao Xu Tan ◽  
Tong Wang ◽  
En Bing Bi
Keyword(s):  
Weibull Distribution ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Tem Analysis ◽  
Average Value ◽  
Nanostructured Ceramic ◽  
Microhardness And Microstructure ◽  
Size Of Particles ◽  
Plasma Sprayed ◽  
The Relationship

Al2O3-13% TiO2 based nanostructured ceramic coatings were prepared on the surface of NiCrAl alloy by Plasma Spraying technology. Compared to the micron ceramic coating (MCC), the average value of hardness of nanostructured ceramic coating (NCC) was much higher than that of MCC, and the NCC presents typical bi-modal distribution. The Weibull distribution of both coatings exhibited apparently dispersible, but NCCs was quite well-distributed. The relationship between microhardness and microstructure were analyzed through SEM, XRD and TEM. The results indicate that the microcracks of NCC are fine and the size of particles is small. The structure of NCC coatings contained more α-Al2O3 and TiO2 and less γ-Al2O3 than that of MCC coatings. According to TEM analysis, it can be considered that the grain refinement, toughening of microcracks, and the dispersive refinement of Al2O3 nanoparticles on Al2O3-TiO2 matrix are main mechanisms to improve the mechanical properties of NCC.

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.

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.

Thermal Barrier Effects Comparison of Plasma-Sprayed and Laser-Remelted Al2O3-13 % TiO2 Ceramic Coatings

2014 ◽  
Vol 978 ◽  
pp. 40-43
Author(s):  
Dong Sheng Wang ◽  
Guang Qu ◽  
Jin Lan Su
Keyword(s):  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Nanostructured Coating ◽  
Thermal Barrier ◽  
Heat Current ◽  
Barrier Effect ◽  
Laser Remelting ◽  
Plasma Sprayed ◽  
Sprayed Coatings ◽  
Conventional Coating

Conventional and nanosturctured Al2O3–13 wt% TiO2ceramic coatings were deposited by plasma spraying on TiAl alloy surface. Laser remelting experiment on as-sprayed coatings was carried out and the influences of laser remelting on microstructure and thermal barrier effect of the coating were researched. The results show that the as-sprayed conventional coating has a typical plasma-sprayed lamellar-like structure, while the nanostructured coating consisted of both fully melted regions and partially melted regions. The laser-remelted conventional coating exhibits column-like crystals which grew along the direction of the heat current, while the nanostructured coating composed of fine equiaxed grains with some remained nanoparticles. The nanostructured ceramic coating has higher thermal barrier effect than the conventional ceramic coating does. The thermal barrier effect of the as-sprayed coatings decreases after laser remelting.

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.

scholarly journals Strain Isolated Ceramic Coatings

1983 ◽  
Author(s):  
R. P. Tolokan ◽  
J. B. Brady ◽  
G. P. Jarrabet
Keyword(s):  
Ceramic Coating ◽  
Combustion Engine ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Turbine Engine ◽  
Shock Testing ◽  
Low Modulus ◽  
Metal Strain ◽  
Fiber Metal ◽  
Plasma Sprayed

The durability of thermally shocked high tempererature ceramic coatings on metal substrates can be dramatically improved using a fiber metal strain isolator between ceramic and metal. The fiber metal strain isolator is a compliant, porous and low modulus material which yields to control the stress on the ceramic coating during thermal cycling. Plasma sprayed strain isolated ceramic coatings .060” (1.5 mm) thick have shown excellent durability in thermal shock testing. The strain isolated ceramic coating is an excellent thermal barrier since both the ceramic and fiber metal are good insulators. Applications include ceramic thermal barrier coatings for gas turbine engine seals and turbine components, combustors, MHD electrodes, and internal combustion engine insulation.

scholarly journals Microstructural Investigation of Plasma Sprayed Ceramic Coatings Using Peridynamics

2020 ◽  
Vol 36 (2) ◽  
pp. 183-196 ◽  
Author(s):  
V. Guski ◽  
W. Verestek ◽  
E. Oterkus ◽  
S. Schmauder
Keyword(s):  
Ceramic Coating ◽  
Heterogeneous Material ◽  
Ceramic Coatings ◽  
Structural Defects ◽  
Microstructural Investigation ◽  
Microstructural Model ◽  
Edge Notch ◽  
Plasma Sprayed ◽  
Good Agreement ◽  
Effective Mechanical Properties

ABSTRACTThe present study deploys a continuum mechanics approach called peridynamics to investigate the damage behaviour of a 2D microstructure, which was taken from a plasma sprayed ceramic coating used in solid oxide fuel cell (SOFC) sealing systems. At the beginning, two benchmark cases, namely, plate with a hole as well as plate with a single edge notch, are considered. The results are compared to an analytical solution and a very good agreement is obtained. Based on these findings, a microstructural model from a plasma sprayed ceramic coating of SOFC sealing systems is investigated. These micromechanical simulations show that structural defects influence the crack initiation as well as the crack propagation during interconnecting the defects. Typical crack mechanisms, such as crack deflection, crack shielding or multiple cracking, are observed. Additionally, an anisotropy of the effective mechanical properties is observed in this heterogeneous material, which is well known for plasma sprayed materials.

Comparative Solid Particle Erosion Characterization of Conventional and Nanostructured Al2O3-13wt.%TiO2 Ceramic Coatings Fabricated by Plasma Spraying Process

2012 ◽  
Vol 463-464 ◽  
pp. 359-363 ◽  
Author(s):  
Dong Sheng Wang ◽  
Zong Jun Tian ◽  
Song Lin Wang ◽  
Li Da Shen
Keyword(s):  
Plasma Spraying ◽  
Solid Particle ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Nanostructured Coating ◽  
Nano Particles ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Nanostructured Ceramic

Abstract. In this work, conventional and nanostructured Al2O3-13wt.%TiO2coatings were deposited by the plasma spraying technique. The microstructures of the two types of coatings were analyzed, and the solid particle erosion behaviors of the two coatings were comparatively researched in an erosion tester. Meanwhile, the erosion failure mechanisms of the coatings were discussed. The results show that the traditional coating has laminated structure and some pores. However, the nanostructured coating possesses a denser structure and not obviously lamellar-like structure, and exhibits a bimodal microstructure consisted of fully melted regions and partially melted regions. Owing to the compact microstructure and remained nano-particles, the nanostructured coating had a better erosion wear resistance than the conventional coating. Eroded morphology analysis indicates the main erosion mass loss of the coatings is attributed to lamellar spalling of the sprayed splats and fracture of brittle ceramic particles. In addition, the nanostructued coating has some impact craters and plough marks. In terms of the erosion mechanism, the conventional ceramic coating is dominated by brittle erosion, while the nanostructured ceramic coating is dominated by brittle erosion as well as ductile erosion to some extent.

Development and implementation of plasma sprayed nanostructured ceramic coatings

2001 ◽  
Vol 146-147 ◽  
pp. 48-54 ◽  
Author(s):  
M Gell ◽  
E.H Jordan ◽  
Y.H Sohn ◽  
D Goberman ◽  
L Shaw ◽  
...  
Keyword(s):  
Ceramic Coatings ◽  
Nanostructured Ceramic ◽  
Plasma Sprayed

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).

scholarly journals Microstructure and Wear Behaviors of Plasma-Sprayed MoAlB Ceramic Coating

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 474
Author(s):  
Fuzhu Li ◽  
Shengnan Sun ◽  
Yong Xu ◽  
Lihui Tian ◽  
Yun Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Plasma Spraying ◽  
Ceramic Coating ◽  
Adhesive Wear ◽  
Ceramic Coatings ◽  
Atmospheric Plasma ◽  
Wear Rates ◽  
Arc Power ◽  
Plasma Sprayed

MoAlB ceramic coatings were prepared on a 316 steel surface by atmospheric plasma spraying with different arc power levels. The phase composition, microstructure and wear resistance of coatings against GCr15 and Si3N4 counterparts were studied. The MoAlB ceramic decomposed and was oxidized to form MoB and Al2O3 during plasma spraying. With the increase of the arc power, MoAlB experienced more decomposition, but the coatings became denser. When the arc power increased from 30 to 36 kW, the wear rates of coatings against GCr15 and Si3N4 balls reduced by 91% and 78%, respectively. The characterization of wear tracks shows that when against GCr15 counterparts, the main wear mechanisms are abrasive and adhesive wear, and when against Si3N4 counterparts, fatigue and abrasive wear are dominant. The refinement of wear resistance by increasing arc power can be attributed to the improvement of density and adhesive strength among splats.

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