Strengthening Mechanism of Al2O3 Ceramic-Lined Composite Steel Pipe Prepared by the SHS Gravitational Separation Process

2018 ◽  
Vol 916 ◽  
pp. 79-84
Author(s):  
Xing Hui Hou ◽  
Jing Kun Yu
Keyword(s):  
Phase Composition ◽  
Ceramic Coating ◽  
Raw Materials ◽  
Reaction System ◽  
Strengthening Mechanism ◽  
Ceramic Coatings ◽  
Separation Process ◽  
Steel Pipe ◽  
Element Contents ◽  
Composite Steel

The Al2O3ceramic-lined composite steel pipes were produced by the SHS gravitational separation process (SHS-GS process) from Al, Fe2O3and Cr2O3as the raw materials within different reaction systems. The phase, composition, micro-structure and properties of ceramic coatings were investigated to discuss the strengthening mechanism of the composite steel pipe. The results showed that the phase composition of Al-Fe2O3-Cr2O3reaction system could be Al2O3and Fe-Cr alloy compared with the Al2O3-Fe-FeAl2O4phases of Al-Fe2O3reaction system, which led to the increase of strength and hardness of ceramic coating. Because the Fe-Cr alloy was formed instead of Fe element, and the addition of Cr2O3reduced the production of erodible FeAl2O4. The transition structure consisted of ceramic coating-transition layer-steel pipe was formed, and in its direction the Al and O element contents decreased, the metallic Fe and Cr increased. Therefore, the transitional changes of all the element contents could decrease the stress difference between the layers, and increase the bonding strength of the composite steel pipe.

Study of the Effect of Feldspar Replacement from a Mixture of Glass / Syenite in Technological Properties of Ceramic Coatings

2014 ◽  
Vol 798-799 ◽  
pp. 294-299 ◽  
Author(s):  
José Elson Soares Filho ◽  
Alan de Oliveira Feitosa ◽  
Leonardo Leandro dos Santos ◽  
Liszandra Fernanda Araújo Campos ◽  
Ricardo Peixoto Suassuna Dutra
Keyword(s):  
Ceramic Coating ◽  
Raw Materials ◽  
Ceramic Coatings ◽  
Standard Formulation ◽  
Technological Properties ◽  
Ceramic Tiles ◽  
Recycled Glass ◽  
Different Temperatures ◽  
Formed Product ◽  
Melting Material

Obtaining new raw materials for the production of ceramic coating is increasingly highlighted, however, it is desirable to maintain or improve the technological properties of the formed product. Thinking about it, and aiming at the environmental context, the aim of this work is to study the mixing recycled glass effect with syenite, an alternative melting often used in the production of ceramic tiles, in replacing to feldspar. The raw materials were characterized and subsequently the technological properties were determined for the standard formulation and the formulations with 5, 10, 15 and 20% mixing glass / syenite, in replacing to feldspar. The test bodies were prepared by wet, and sintered at different temperatures, with a rate of 30 °C /min and a level of 20 minutes. The results indicate that the mixing glass / syenite has the potential to be used as melting material in the composition of the ceramic mass.

Study on the Structural Analysis of Al2O3 Ceramic-Lined Steel Pipe Prepared with the Gravitational Separation SHS Method

2018 ◽  
Vol 759 ◽  
pp. 59-64 ◽  
Author(s):  
Xing Hui Hou ◽  
Jing Kun Yu ◽  
Xin Yang ◽  
Zhao Yang Liu
Keyword(s):  
Transition Layer ◽  
Ceramic Coating ◽  
Molecular Diffusion ◽  
Great Influence ◽  
Reaction System ◽  
Steel Pipe ◽  
Reaction Products ◽  
Transition Structure ◽  
Diffusion Motion ◽  
Shs Method

One kind of Al2O3 ceramic-lined steel pipe was prepared with the gravitational separation SHS method by using the reaction system of Al-Fe2O3-Cr2O3. The element line scans of transition structure and the element plane scans of ceramic coating far away from transition layer were analyzed by Scanning Electron Microscopy and Energy Dispersive Spectroscopy, and then they were used to discuss the coating structure and interface bonding mechanism, and investigate the element composition distribution of coating. All of these were closely related to improving the properties of ceramic-lined steel pipe. The results showed that a transition layer was formed between metal pipe and ceramic coating, it was due to the gravitational separation and molecular diffusion motion of the reaction products in molten state; in the transition structure the amount of the reaction elements was gradually transitional from the direction of the coating-transition layer-steel pipe, which could reduce the stress difference between the layers; in the coating far away from the transition layer, only small amount of Fe embedded in the ceramic was left in the form of Fe-Cr alloy, while Cr was uniformly enriched in the Al2O3 ceramic, these all have great influence on the anti-corrosion ability of coating.

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.

Influences of Calcination Ambiences on Phase Composition and High Temperature Oxidation Resistance Property of Ceramic Coatings on Ti–6Al–4V Alloy by Micro-Plasma Oxidation

2007 ◽  
Vol 336-338 ◽  
pp. 2481-2483 ◽  
Author(s):  
Guo Dong Hao ◽  
Zhao Hua Jiang ◽  
Zhong Ping Yao ◽  
Heng Ze Xian ◽  
Yan Li Jiang
Keyword(s):  
Phase Composition ◽  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Ceramic Coatings ◽  
Plasma Oxidation ◽  
Temperature Oxidation ◽  
Complete Decomposition ◽  
Weight Gains ◽  
High Temperature Calcination

Compound ceramic coatings with the main crystalline of Al2TiO5 (as-coated samples) were prepared on Ti-6Al-4V alloy by pulsed bi-polar micro-plasma oxidation (MPO) in NaAlO2 solution. The coated samples were calcined in Ar and air at 1000oC, respectively. The phase composition, morphology and element content of the coatings were investigated by XRD, SEM and XRF. The samples treated in Ar and the as-coated ones were calcined in air at 1000oC to study the oxidation resistance of the samples. The results showed that Al2TiO5 decomposed and transformed into corundum and rutile TiO2 during the high temperature calcination. Al2TiO5 decomposed very quickly in air and the proportion of Al2O3 to TiO2 was 44:55 after a complete decomposition. On the contrary, Al2TiO5 decomposed very slowly in argon with the final proportion of Al2O3 to TiO2 of 81:18 on the coating surface. The morphology of the ceramic coatings after the calcination was also different. The coatings calcined in argon were fined: the grains and pores were smaller than those of the coatings calcined in air. The weight gains of both coatings changed in the form of parabola law, and the weight gains of the coated samples treated in argon were comparatively lower than that of the as-coated samples. During the high temperature calcination, the samples treated in argon cannot distort easily, compared with the as-coated ones.

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.

Preparation of Rutile Crystalline Glaze

2010 ◽  
Vol 105-106 ◽  
pp. 778-781
Author(s):  
Yin Feng Xia ◽  
Zhao Hui Huang ◽  
Jia Zheng Yuan ◽  
Lin Jun Wang ◽  
Jie Hua Xie
Keyword(s):  
Phase Composition ◽  
Crystallization Process ◽  
Raw Materials ◽  
Flower Morphology ◽  
Processing Conditions ◽  
Single Track ◽  
Spontaneous Growth ◽  
Microscopy Analysis ◽  
Coloring Agents ◽  
Aesthetic Values

Crystalline glaze is a kind of art glaze with excellent decorative performance, the existing crystalline glaze mainly willemite crystalline glaze, systems on a single track. In this paper, the use of crystalline glaze raw materials for glass, ZnO and coke gemstones, CuO as coloring agents, using ortho- gonal to determine the formula, this paper researched that added TiO2 to the willemite crystalline glaze crystal phase composition as well as the amount of TiO2 and processing conditions on the preparation of crystalline glaze crystal flower morphology impact. The results show that under the conditions of 1250°C melting 1130°C crystallization process crystal spontaneous growth in crystalline glaze can be able to cover the entire glazed, shape of crystals was feathered, cross growth, the number of crystal increased with crystallization temperature, glaze was smooth and shiny sense. XRD and optical microscopy analysis showed that the precipitation of crystals was the long column of rutile, crystal distributed equality, under a polarizing microscope in purple, green and black, with strong aesthetic values.

scholarly journals Correlation between Yield and Reduced Mass of Raw Materials in Intermolecular and Intramolecular Cyclization Reactions

2020 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Intramolecular Cyclization ◽  
Raw Materials ◽  
Reaction System ◽  
Diels Alder ◽  
Regression Equation ◽  
Reaction Site ◽  
Coupling Reactions ◽  
Cyclization Reactions ◽  
Intermolecular Reaction ◽  
Intermolecular Reactions

Correlation between yield and reduced mass of raw materials in intramolecular C-N, C-C, C-O coupling reactions and intramolecular/intermolecular Diels-Alder reactions was revealed. The regression equation was found to be the same as that of intermolecular reactions; yield = -0.1861<i>M</i><sub>AB</sub>/(<i>n</i><sub>A</sub><i>n</i><sub>B</sub><i>n</i><sub>I</sub>)+100.0, where <i>M</i><sub>AB</sub> is the reduced mass per mole and <i>n</i><sub>A</sub> and <i>n</i><sub>B</sub> are the total number of each reaction site in molecular A and molecular B in the reaction system, and <i>n</i><sub>I</sub> is the number to distinguish whether it is a intramolecular reaction or intermolecular reaction.

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