Search results for: paint coating thickness
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2217

Search results for: paint coating thickness

2187 Cold Spray Fabrication of Coating for Highly Corrosive Environment

Authors: Harminder Singh

Abstract:

Cold spray is a novel and emerging technology for the fabrication of coating. In this study, coating is successfully developed by this process on superalloy surface. The selected coating composition is already proved as corrosion resistant. The microstructure of the newly developed coating is examined by various characterization techniques, for testing its suitability for high temperature corrosive conditions of waste incinerator. The energy producing waste incinerators are still running at low efficiency, mainly due to their chlorine based highly corrosive conditions. The characterization results show that the developed cold sprayed coating structure is suitable for its further testing in highly aggressive conditions.

Keywords: coating, cold spray, corrosion, microstructure

Procedia PDF Downloads 353
2186 Anti-Bubble Painting Booth for Wood Coating Resins

Authors: Abasali Masoumi, Amir Gholamian Bozorgi

Abstract:

To have the best quality in wood products such as tabletops and inlay-woods, applying two principles are required: aesthetic and protection against the destructive agent. Artists spent a lot of time creating a masterwork project and also for better demonstrating beautiful appearance and preserving it for hundred years. So they need good material and appropriate method to finish it. As usual, wood painters use polyester or epoxy resins. These finishes need a special skill to use and then give a fantastic paint film and clearness. If we let resins dry in exposure to environmental agents such as unstable temperature, dust and etc., no doubt it becomes cloudy, crack, blister and much wood dust and air bubbles in it. We have designed a special wood coating booth (IR-Patent No: 70429) for wood-coating resins (polyester and epoxy), and this booth provides an adjustable space to control factors that is necessary to have a good finish in the end. Anti-bubble painting booth has the ability to remove bubbles from resin, precludes the cracking process and causes the resin to be the best. With this booth drying time of resin is reduced from 24 hours to 6 hours by fixing the optimum temperature, and it is very good for saving time. This booth is environment-friendly and never lets the poisonous vapors and other VOC (Volatile organic components) enter to workplace atmosphere because they are very harmful to humans.

Keywords: wood coating, epoxy resin, polyester resin, wood finishes

Procedia PDF Downloads 188
2185 Physicochemical Characterization of Medium Alkyd Resins Prepared with a Mixture of Linum usitatissimum L. and Plukenetia volubilis L. Oils

Authors: Antonella Hadzich, Santiago Flores

Abstract:

Alkyds have become essential raw materials in the coating and paint industry, due to their low cost, good application properties and lower environmental impact in comparison with petroleum-based polymers. The properties of these oil-modified materials depend on the type of polyunsaturated vegetable oil used for its manufacturing, since a higher degree of unsaturation provides a better crosslinking of the cured paint. Linum usitatissimum L. (flax) oil is widely used to develop alkyd resins due to its high degree of unsaturation. Although it is intended to find non-traditional sources and increase their commercial value, to authors’ best knowledge a natural source that can replace flaxseed oil has not yet been found. However, Plukenetia volubilis L. oil, of Peruvian origin, contains a similar fatty acid polyunsaturated content to the one reported for Linum usitatissimum L. oil. In this perspective, medium alkyd resins were prepared with a mixture of 50% of Linum usitatissimum L. oil and 50% of Plukenetia volubilis L. oil. Pure Linum usitatissimum L. oil was also used for comparison purposes. Three different resins were obtained by varying the amount of glycerol and pentaerythritol. The synthesized alkyd resins were characterized by FT-IR, and physicochemical properties like acid value, colour, viscosity, density and drying time were evaluated by standard methods. The pencil hardness and chemical resistance behaviour of the cured resins were also studied. Overall, it can be concluded that medium alkyd resins containing Plukenetia volubilis L. oil have an equivalent behaviour compared to those prepared purely with Linum usitatissimum L. oil. Both Plukenetia volubilis L. oil and pentaerythritol have a remarkable influence on certain physicochemical properties of medium alkyd resins.

Keywords: alkyd resins, flaxseed oil, pentaerythritol, Plukenetia volubilis L. oil, protective coating

Procedia PDF Downloads 94
2184 Characterization of Nano Coefficient of Friction through Lfm of Superhydrophobic/Oleophobic Coatings Applied on 316l Ss

Authors: Hamza Shams, Sajid Saleem, Bilal A. Siddiqui

Abstract:

This paper investigates the coefficient of friction at nano-levels of commercially available superhydrophobic/oleophobic coatings when applied over 316L SS. 316L Stainless Steel or Marine Stainless Steel has been selected for its widespread uses in structures, marine and biomedical applications. The coatings were investigated in harsh sand-storm and sea water environments. The particle size of the sand during the procedure was carefully selected to simulate sand-storm conditions. Sand speed during the procedure was carefully modulated to simulate actual wind speed during a sand-storm. Sample preparation was carried out using prescribed methodology by the coating manufacturer. The coating’s adhesion and thickness was verified before and after the experiment with the use of Scanning Electron Microscopy (SEM). The value for nano-level coefficient of friction has been determined using Lateral Force Microscopy (LFM). The analysis has been used to formulate a value of friction coefficient which in turn is associative of the amount of wear the coating can bear before the exposure of the base substrate to the harsh environment. The analysis aims to validate the coefficient of friction value as marketed by the coating manufacturers and more importantly test the coating in real-life applications to justify its use. It is expected that the coating would resist exposure to the harsh environment for a considerable amount of time. Further, it would prevent the sample from getting corroded in the process.

Keywords: 316L SS, scanning electron microscopy, lateral force microscopy, marine stainless steel, oleophobic coating, superhydrophobic coating

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2183 Effect of Pack Aluminising Conditions on βNiAl Coatings

Authors: A. D. Chandio, P. Xiao

Abstract:

In this study, nickel aluminide coatings were deposited onto CMSX-4 single crystal superalloy and pure Ni substrates by using in-situ chemical vapour deposition (CVD) technique. The microstructural evolutions and coating thickness (CT) were studied upon the variation of processing conditions i.e. time and temperature. The results demonstrated (under identical conditions) that coating formed on pure Ni contains no substrate entrapments and have lower CT in comparison to one deposited on the CMSX-4 counterpart. In addition, the interdiffusion zone (IDZ) of Ni substrate is a γ’-Ni3Al in comparison to the CMSX-4 alloy that is βNiAl phase. The higher CT on CMSX-4 superalloy is attributed to presence of γ-Ni/γ’-Ni3Al structure which contains ~ 15 at.% Al before deposition (that is already present in superalloy). Two main deposition parameters (time and temperature) of the coatings were also studied in addition to standard comparison of substrate effects. The coating formation time was found to exhibit profound effect on CT, whilst temperature was found to change coating activities. In addition, the CT showed linear trend from 800 to 1000 °C, thereafter reduction was observed. This was attributed to the change in coating activities.

Keywords: βNiAl, in-situ CVD, CT, CMSX-4, Ni, microstructure

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2182 Electroless Nickel Boron Deposition onto the SiC and B4C Ceramic Reinforced Materials

Authors: I. Kerti, G. Sezen, S. Daglilar

Abstract:

This present work is focused on studying to improve low wetting behaviour between liquid metal and ceramic particles. Ceramic particles like SiC and B4C have attracted great attention because of their usability as reinforcement for composite materials. However, poor wettability of particles is one of the major drawbacks of metal matrix composite production. Various methods have been studied to enhance the wetting properties between ceramic materials and metal substrates during ceramic reinforced metal matrix composites. Among these methods, autocatalytic nickel deposition is a unique process for the enhancement of the surface properties of ceramic particles. In fact, it is difficult to obtain continuous and uniform metallic coating on ceramic powders. In this study deposition of nickel boron layer on ceramic particles via autocatalytic plating in borohydride baths were investigated. Firstly, powders with different particle sizes were sensitized and activated respectively in order to ensure catalytic properties. Following the pre-treatment operations, particles were transferred into the coating bath containing nickel sulphate or nickel chloride as the Ni2+ source. The results show that a better bonding and uniform coating layer were obtained for Ni-B coatings with the Ni2+ source of NiCl2.6H2O as compared to NiSO4.6H2O. With the progress of the time, both particle surfaces are completely covered by a continuous and thin nickel boron layer. The surface morphology of the coatings that were analysed using scanning electron microscopy (SEM) show that SiC and B4C particles both distributed and different thickness of Ni-B nanolayers have been successfully coated onto the particles. The particles were mounted into a polimeric resin and polished in order to observe the thickness and the continuity of the coating layer. The composition of the coating layers were also evaluated by EDS analyses. The SEM morphologies and the EDS results of the coatings at different reaction times were adopted for detailed discussion of the Ni-B electroless plating mechanism.

Keywords: boron carbide, electroless coating, nickel boron deposition, silicon carbide

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2181 Design of Ternary Coatings System to Minimize the Residual Solvent in Polymeric Coatings

Authors: Jyoti Sharma, Raj Kumar Arya

Abstract:

The coatings of homogeneous ternary solution of Poly(styrene)(PS)-Poly(ethyleneglycol)-6000(PEG) Chlorobenzene (CLB) of two different concentrations (5.05%-4.98%-89.97% and 10.05%-5.12%-84.82%) were studied and dried under quiescent conditions. Residual solvent percentage and coatings thickness were calculated by gravimetric weight loss data. Residual solvent remained lower in case of the single thick layer as compared to layer-by-layer assembly technique. The Results suggests the effectiveness of the single thick layer for minimizing the residual solvent. A single thick layer had an initial coating thickness of 1098 µm and the final thickness of 106 µm which is lower as compared to the dried coatings of nearly the same final thickness by layer-by-layer assembly technique.

Keywords: films, layer-by-layer assembly, polymeric coatings, ternary system

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2180 Characterization and Effect of Using Pumpkin Seeds Oil Methyl Ester (PSME) as Fuel in a LHR Diesel Engine

Authors: Hanbey Hazar, Hakan Gul, Ugur Ozturk

Abstract:

In order to decrease the hazardous emissions of the internal combustion engines and to improve the combustion and thermal efficiency, thermal barrier coatings are applied. In this experimental study, cylinder, piston, exhaust, and inlet valves which are combustion chamber components have been coated with a ceramic material, and this earned the engine LHR feature. Cylinder, exhaust and inlet valves of the diesel engine used in the tests were coated with ekabor-2 commercial powder, which is a ceramic material, to a thickness of 50 µm, by using the boriding method. The piston of a diesel engine was coated in 300 µm thickness with bor-based powder by using plasma coating method. Pumpkin seeds oil methyl ester (PSME) was produced by the transesterification method. In addition, dimethoxymethane additive materials were used to improve the properties of diesel fuel, pumpkin seeds oil methyl ester (PSME) and its mixture. Dimethoxymethane was blended with test fuels, which was used as a pilot fuel, at the volumetric ratios of 4% and 8%. Due to thermal barrier coating, the diesel engine's CO, HC, and smoke density values decreased; but, NOx and exhaust gas temperature (EGT) increased.

Keywords: boriding, diesel engine, exhaust emission, thermal barrier coating

Procedia PDF Downloads 453
2179 Technology of Thermal Spray Coating Machining

Authors: Jana Petrů, Tomáš Zlámal, Robert Čep, Lenka Čepová

Abstract:

This article is focused on the thermal spray coating machining issue. Those are irreplaceable in many areas of nowadays industrial branches such as aerospace industry, mostly thanks to their excellent qualities in production and also in renovation of machinery parts. The principals of thermal spraying and elementary diversification are described in introduction. Plasma coating method of composite materials -cermets- is described more thoroughly. The second part describes thermal spray coating machining and grinding in detail. This part contains suggestion of appropriate grinding tool and assessment of cutting conditions used for grinding a given part. Conclusion describes a problem which occurred while grinding a cermet thermal spray coating with a specially designed grindstone and a way to solve this problem.

Keywords: coating, aerospace, plasma, grinding

Procedia PDF Downloads 519
2178 Monocrystalline Silicon Surface Passivation by Porous Silicon

Authors: Mohamed Ben Rabha

Abstract:

In this paper, we report on the effect of porous silicon (PS) treatment on the surface passivation of monocrystalline silicon (c-Si). PS film with a thickness of 80 nm was deposited by stain etching. It was demonstrated that PS coating is a very interesting solution for surface passivation. The level of surface passivation is determined by techniques based on photoconductance and FTIR. As a results, the effective minority carrier lifetime increase from 2 µs to 7 µs at ∆n=1015 cm-3 and the reflectivity reduce from 28 % to about 7 % after PS coating.

Keywords: porous silicon, effective minority carrier lifetime, reflectivity

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2177 Analyzing the Efficiency of Several Gum Extraction Tapping Systems for Wood Apple Trees

Authors: K. M. K. D Weerasekara, R. M. K. M Rathnayake, R. U. Halwatura, G. Y. Jayasinghe

Abstract:

Wood apple (Limonia acidissima L.) trees are native to Sri Lanka and India. Wood apple gum is widely used in the food, coating, and pharmaceutical industries. Wood apple gum was a major component in ancient Sri Lankan coating technology as well. It is also used as a suspending agent in liquid syrups and food ingredients such as sauces, emulsifiers, and stabilizers. Industrial applications include adhesives for labeling and packaging, as well as paint binder. It is also used in the production of paper and cosmetics. Extraction of wood apple gum is an important step in ensuring maximum benefits for various uses. It is apparent that an abundance of untapped potential lies in wood apple gum if people are able to mass produce them. Hence, the current study uses a two-factor factorial design with two major variables and four replications to investigate the best gum-extracting tapping system for Wood apple gum. This study's findings will be useful to Wood apple cultivators, researchers, and gum-based industries alike.

Keywords: wood apple gum, limonia acidissima l., tapping, tapping cuts

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2176 Surface Coatings of Boards Made from Alternative Materials

Authors: Stepan Hysek, Petra Gajdacova

Abstract:

In recent years, alternative materials, such as annual plants or recycled and waste materials are becoming more and more popular input material for the production of composite materials. They can be used for the production of insulation boards, construction boards or furniture boards. Surface finishing of those boards is essential for utilization in furniture. However, some difficulties could occur during coating of boards from alternative materials; physical and chemical differences from conventional particleboards need to be considered. From the physical aspects, surface soundness and surface roughness mainly determine the quality of the surface. Since surface layers of boards from alternative materials have often lower density, these characteristics could be deteriorated and thus the production process needs to be optimized. Also, chemical reactions of board’s material with coating could be undesirable. The objective of this study is to evaluate the parameters affecting the surface quality of boards made form alternative materials and to find possibilities of the coating of these boards. In this study, boards of particles from rapeseed stems were produced using a laboratory press. Surface soundness, as representatives of mechanical properties and surface roughness, as representative of physical properties, were measured on boards from rapeseed stems. Results clearly indicated that produced boards had lower surface quality than commercially produced particle boards from wood. Therefore, higher thickness of surface coating on rapeseed based boards is needed.

Keywords: coating, surface, annual plant, composites, particleboard

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2175 Psyllium (Plantago) Gum as an Effective Edible Coating to Improve Quality and Shelf Life of Fresh-Cut Papaya (Carica papaya)

Authors: Basharat Yousuf, Abhaya K. Srivastava

Abstract:

Psyllium gum alone and in combination with sunflower oil was investigated as a possible alternative edible coating for improvement of quality and shelf life of fresh-cut papaya. Different concentrations including 0.5, 1 and 1.5 percent of psyllium gum were used for coating of fresh-cut papaya. In some samples, refined sunflower oil was used as a lipid component to increase the effectiveness of coating in terms of water barrier properties. Soya lecithin was used as an emulsifier in coatings containing oil. Pretreatment with 1% calcium chloride was given to maintain the firmness of fresh-cut papaya cubes. 1% psyllium gum coating was found to yield better results. Further, addition of oil helped to maintain the quality and acted as a barrier to water vapour, therefore, minimizing the weight loss.

Keywords: coating, fresh-cut, gum, papaya, psylllium

Procedia PDF Downloads 478
2174 The Performance of Typical Kinds of Coating of Printed Circuit Board under Accelerated Degradation Test

Authors: Xiaohui Wang, Liwei Sun, Guilin Zhang

Abstract:

Printed circuit board (PCB) is the carrier of electronic components. Its coating is the first barrier for protecting itself. If the coating is damaged, the performance of printed circuit board will decrease rapidly until failure. Therefore, the coating plays an important role in the entire printed circuit board. There are common four kinds of coating of printed circuit board that the material of the coatings are paryleneC, acrylic, polyurethane, silicone. In this paper, we designed an accelerated degradation test of humid and heat for these four kinds of coating. And chose insulation resistance, moisture absorption and surface morphology as its test indexes. By comparing the change of insulation resistance of the coating before and after the test, we estimate failure time of these coatings based on the degradation of insulation resistance. Based on the above, we estimate the service life of the four kinds of PCB.

Keywords: printed circuit board, life assessment, insulation resistance, coating material

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2173 Meniscus Guided Film Coating for Large-Area Perovskite Solar Cells

Authors: Gizachew Belay Adugna, Yu-Tai Tao

Abstract:

Perovskite solar cells (PSCs) have been gaining impressive progress with excellent power conversion efficiency (PCE) of 25.5% in small-area devices. However, the conventional film coating approach is not applicable to large-area module fabrication. Meniscus-guided coating, including blade coating, slot-die coating, and bar coating, is solution processing and promising for large-area and cost-effective film coating to industrial-scale PSCs. Here, we develop simple and scalable solution shearing (SS) and bar coating (BC) methods to coat all layers on large-area (10x10 cm²) substrate in FTO/c-TiO₂/mp-TiO₂/ CH₃NH₃PbI₃/Spiro-OMeTAD/Ag device structure, except the Ag electrode. All solution-sheared PSC exhibited a champion power conversion efficiency of 15.89% in the conational DMF/DMSO solvent. Whereas a very high PCE of 20.30% compared to the controlled spin-coated device (SC, 17.60%) was achieved from the large area sheared perovskite film in a green ACN/MA solvent. Similarly, a remarkable PCE of 18.50% was achieved for a device fabricated from a large-area perovskite film in a simpler and more compatible Bar-coating system. This strategy demonstrates the huge potential for module fabrication and future PSC commercialization.

Keywords: Perovskite solar cells, larger area film coating, meniscus-guided film coating, solution-shearing, bar-coating, power conversion efficiency

Procedia PDF Downloads 41
2172 Preparation of Protective Coating Film on Metal Alloy

Authors: Rana Th. A. Al-rubaye

Abstract:

A novel chromium-free protective coating films based on a zeolite coating was growing onto a FeCrAlloy metal using in –situ hydrothermal method. The zeolite film was obtained using in-situ crystallization process that is capable of coating large surfaces with complex shape and in confined spaces has been developed. The zeolite coating offers an advantage of a high mechanical stability and thermal stability. The physico-chemical properties were investigated using X-ray diffraction (XRD), Electron microscopy (SEM), Energy Dispersive X–ray analysis (EDX) and Thermogravimetric Analysis (TGA). The transition from oxide-on-alloy wires to hydrothermally synthesised uniformly zeolite coated surfaces was followed using SEM and XRD. In addition, the robustness of the prepared coating was confirmed by subjecting these to thermal cycling (ambient to 550°C).

Keywords: fecralloy, zsm-5 zeolite, zeolite coatings, hydrothermal method

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2171 Sound Performance of a Composite Acoustic Coating With Embedded Parallel Plates Under Hydrostatic Pressure

Authors: Bo Hu, Shibo Wang, Haoyang Zhang, Jie Shi

Abstract:

With the development of sonar detection technology, the acoustic stealth technology of underwater vehicles is facing severe challenges. The underwater acoustic coating is developing towards the direction of low-frequency absorption capability and broad absorption frequency bandwidth. In this paper, an acoustic model of underwater acoustic coating of composite material embedded with periodical steel structure is presented. The model has multiple high absorption peaks in the frequency range of 1kHz-8kHz, where achieves high sound absorption and broad bandwidth performance. It is found that the frequencies of the absorption peaks are related to the classic half-wavelength transmission principle. The sound absorption performance of the acoustic model is investigated by the finite element method using COMSOL software. The sound absorption mechanism of the proposed model is explained by the distributions of the displacement vector field. The influence of geometric parameters of periodical steel structure, including thickness and distance, on the sound absorption ability of the proposed model are further discussed. The acoustic model proposed in this study provides an idea for the design of underwater low-frequency broadband acoustic coating, and the results shows the possibility and feasibility for practical underwater application.

Keywords: acoustic coating, composite material, broad frequency bandwidth, sound absorption performance

Procedia PDF Downloads 140
2170 Influence of Machining Process on Surface Integrity of Plasma Coating

Authors: T. Zlámal, J. Petrů, M. Pagáč, P. Krajkovič

Abstract:

For the required function of components with the thermal spray coating, it is necessary to perform additional machining of the coated surface. The paper deals with assessing the surface integrity of Metco 2042, a plasma sprayed coating, after its machining. The selected plasma sprayed coating serves as an abradable sealing coating in a jet engine. Therefore, the spray and its surface must meet high quality and functional requirements. Plasma sprayed coatings are characterized by lamellar structure, which requires a special approach to their machining. Therefore, the experimental part involves the set-up of special cutting tools and cutting parameters under which the applied coating was machined. For the assessment of suitably set machining parameters, selected parameters of surface integrity were measured and evaluated during the experiment. To determine the size of surface irregularities and the effect of the selected machining technology on the sprayed coating surface, the surface roughness parameters Ra and Rz were measured. Furthermore, the measurement of sprayed coating surface hardness by the HR 15 Y method before and after machining process was used to determine the surface strengthening. The changes of strengthening were detected after the machining. The impact of chosen cutting parameters on the surface roughness after the machining was not proven.

Keywords: machining, plasma sprayed coating, surface integrity, strengthening

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2169 Enhancement of the Corrosion Resistance of Fastening System of Ballasted ‎Railway in Sandy Desert by Using Nano-Coating

Authors: Milad Alizadeh Galdiani, Navid Sabet, Mohamad Ali Mohit, Fatemeh Palizdar

Abstract:

Railway as one of the most important transportation modes, passes through ‎various areas with different conditions ‎inevitably, and in many countries such as ‎China, United States, Australia, and Iran, it passes through sandy ‎desert areas. One ‎of the main problems in these areas is the movement of sand, causing various ‎damages ‎to ballasted railway track such as corrosion in the railway fastening system. ‎The soil composition of some desert areas like Fahraj in Iran consists of sand ‎and ‎salt. Due to the movement of sand and corrosive ions of salt, the fastening system ‎of the railway is ‎corroded, which, in turn, reduces the thickness of the components ‎and their life span.‎ In this research, the Nano-coating for fastening system of ‎the railway is ‎introduced, and its performance has been investigated in both ‎laboratory and field tests. The Nano-coating of ‎the fastening system consists of zinc-rich, epoxy, polyurethane, and additive, which is produced through ‎Nano ‎technology. This layer covers the surface of the fastening system and ‎prohibits the chemical reactions, which result in ‎corrosion. The results of ‎Electrochemical Impedance Spectroscopy (EIS) ‎indicate that corrosion resistance ‎increases 315 times by using nano-coating, salt spray test results demonstrate that ‎nano-coated components remained intact after 1000 hours.‎

Keywords: ballasted railway, Nano-coating, railway fastening system, sandy desert

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2168 Effect of the Vertical Pressure on the ‎Electrical Behaviour of the Micro-Copper ‎Polyurethane Composite Films

Authors: Saeid Mehvari, Yolanda Sanchez-Vicente, Sergio González Sánchez, Khalid Lafdi

Abstract:

Abstract- Materials with a combination of transparency, electrical conductivity, and flexibility are required in the ‎growing electronic sector. In this research, electrically conductive and flexible films have been prepared. These ‎composite films consist of dispersing micro-copper particles into polyurethane (PU) matrix. Two sets of samples were ‎made using both spin coating technique (sample thickness lower than 30 μm) and materials casting (sample thickness ‎lower than 100 μm). Copper concentrations in the PU matrix varied from 0.5 to 20% by volume. The dispersion of ‎micro-copper particles into polyurethane (PU) matrix were characterised using optical microscope and scanning electron ‎microscope. The electrical conductivity measurement was carried out using home-made multimeter set up under ‎pressures from 1 to 20 kPa through thickness and in plane direction. It seems that samples made by casting were not ‎conductive. However, the sample made by spin coating shows through-thickness conductivity when they are under ‎pressure. The results showed that spin-coated films with higher concentration of 2 vol. % of copper displayed a ‎significant increase in the conductivity value, known as percolation threshold. The maximum conductivity of 7.2 × 10-1 ‎S∙m-1 was reached at concentrations of filler with 20 vol. % at 20kPa. A semi-empirical model with adjustable ‎coefficients was used to fit and predict the electrical behaviour of composites. For the first time, the finite element ‎method based on the representative volume element (FE-RVE) was successfully used to predict their electrical ‎behaviour under applied pressures. ‎

Keywords: electrical conductivity, micro copper, numerical simulation, percolation threshold, polyurethane, RVE model

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2167 Studies on Plasma Spray Deposited La2O3 - YSZ (Yttria-Stabilized Zirconia) Composite Thermal Barrier Coating

Authors: Prashant Sharma, Jyotsna Dutta Majumdar

Abstract:

The present study concerns development of a composite thermal barrier coating consisting of a mixture of La2O3 and YSZ (with 8 wt.%, 32 wt.% and 50 wt.% 50% La2O3) by plasma spray deposition technique on a CoNiCrAlY based bond coat deposited on Inconel 718 substrate by high velocity oxy-fuel deposition (HVOF) technique. The addition of La2O3 in YSZ causes the formation of pyrochlore (La2Zr2O7) phase in the inter splats boundary along with the presence of LaYO3 phase. The coefficient of thermal expansion is significantly reduced from due to the evolution of different phases and structural defects in the sprayed coating. The activation energy for TGO growth under isothermal and cyclic oxidation was increased in the composite coating as compared to YSZ coating.

Keywords: plasma spraying, oxidation resistance, thermal barrier coating, microstructure, X-ray method

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2166 Spent Paint Solvent Recoveries by Ionic Liquids: Potential for Industrial Application

Authors: Mbongeni Mabaso, Kandasamy Moodley, Gan Redhi

Abstract:

The recovery of industrially valuable organic solvents from liquid waste, generated in chemical processes, is economically crucial to countries which need to import organic solvents. In view of this, the main objective of this study was to determine the ability of selected ionic liquids, namely, 1-ethyl-3-methylimidazolium ethylsulphate, [EMIM] [ESO4] and 1-ethyl-3-methylpyridinium ethylsulphate, [EMpy][ESO4] to recover aromatic components from spent paint solvents. Preliminary studies done on the liquid waste, received from a paint manufacturing company, showed that the aromatic components were present in the range 6 - 21 % by volume. The separation of the aromatic components was performed with the ionic liquids listed above. The phases, resulting from the separation of the mixtures, were analysed with a Gas Chromatograph (GC) coupled to a FID detector. Chromatograms illustrate that the chosen ZB-Wax-Plus column gave excellent separation of all components of interest from the mixtures, including the isomers of xylene. The concentrations of aromatics recovered from the spent solvents were found to be the % ranges 13-33 and 23-49 respectively for imidazolium and pyridinium ionic liquids. These results also show that there is a significant correlation between π-character of ionic liquids and the level of extraction. It is therefore concluded that ionic liquids have the potential for macro-scale recovery of re-useable solvents present in liquid waste emanating from paint manufacture.

Keywords: synthesis, ionic liquid, imidazolium, pyridinium, extraction, aromatic solvents, spent paint organic solvents

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2165 Dimensionally Stable Anode as a Bipolar Plate for Vanadium Redox Flow Battery

Authors: Jaejin Han, Jinsub Choi

Abstract:

Vanadium redox flow battery (VRFB) is a type of redox flow battery which uses vanadium ionic solution as electrolyte. Inside the VRFB, 2.5mm thickness of graphite is generally used as bipolar plate for anti-corrosion of current collector. In this research, thick graphite bipolar plate was substituted by 0.126mm thickness of dimensionally stable anode which was coated with IrO2 on an anodic nanotubular TiO2 substrate. It can provide dimensional advantage over the conventional graphite when the VRFB is used as multi-stack. Ir was coated by using spray coating method in order to enhance electric conductivity. In this study, various electrochemical characterizations were carried out. Cyclic voltammetry data showed activation of Ir in the positive electrode of VRFB. In addition, polarization measurements showed Ir-coated DSA had low overpotential in the positive electrode of VRFB. In cell test results, the DSA-used VRFB showed better efficiency than graphite-used VRFB in voltage and overall efficiency.

Keywords: bipolar plate, DSA (dimensionally stable anode), iridium oxide coating, TiO2 nanotubes, VRFB (vanadium redox flow battery)

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2164 Titanium-Aluminium Oxide Coating on Aluminized Steel

Authors: Fuyan Sun, Guang Wang, Xueyuan Nie

Abstract:

In this study, a plasma electrolytic oxidation (PEO) process was used to form titanium-aluminium oxide coating on aluminized steel. The present work was mainly to study the effects of treatment time of PEO process on properties of the titanium coating. A potentiodynamic polarization corrosion test was employed to investigate the corrosion resistance of the coating. The friction coefficient and wear resistance of the coating were studied by using pin-on-disc test. The thermal transfer behaviours of uncoated and PEO-coated aluminized steels were also studied. It could be seen that treatment time of PEO process significantly influenced the properties of the titanium oxide coating. Samples with a longer treatment time had a better performance for corrosion and wear protection. This paper demonstrated different treatment time could alter the surface behaviour of the coating material.

Keywords: titanium-aluminum oxide, plasma electrolytic oxidation, corrosion, wear, thermal property

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2163 The Use of the Steel Aggregate and Procedures for Application on Rural Roads to Improve Traffic

Authors: Luís Felipe da Cunha Mendonça

Abstract:

Normally, rural roads do not have any type of coating, and when they have any coating, they have a high maintenance cost due to the characteristics of natural materials. The Steel Aggregate has specific technical characteristics, which considerably reduce the maintenance costs of rural roads with the execution of the Primary Coating. For use as a primary coating, it must be mixed with clay due to the physical-chemical properties of the material. The application is mainly in the Primary Coating of rural roads due to the cementitious property in the presence of water, offering greater resistance to wear caused by traffic and consequently a longer useful life of the coating. The Steel Aggregate executed on rural roads has reduced particulate emissions and offers normal traffic in any weather condition, as well as creating sustainability. Contribute to the quality of life of communities through improvements in the conditions of rural and urban unpaved roads. Leading to substantial savings in maintenance. Because the durability, if applied correctly, is about 3 years, but if annual monitoring is carried out, it can be extended for more than 5 years.

Keywords: steel slag, co-product, primary coating, steel aggregate

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2162 Leading Edge Vortex Development for a 65° Delta Wing with Varying Thickness and Maximum Thickness Locations

Authors: Jana Stucke, Sean Tuling, Chris Toomer

Abstract:

This study focuses on the numerical investigation of the leading edge vortex (LEV) development over a 65° swept delta wing with varying thickness and maximum thickness location and their impact on its overall performance. The tested configurations are defined by a 6% and 12 % thick biconvex aerofoil with maximum thickness location at 30% and 50% of the root chord. The results are compared to a flat plate delta wing configuration of 3.4% thickness. The largest differences are observed for the aerofoils of 12% thickness and are used to demonstrate the trends and aerodynamic characteristics from here on. It was found that the vortex structure changes with change with maximum thickness and overall thickness. This change leads to not only a reduction in lift but also in drag, especially when the maximum thickness is moved forward. The reduction in drag, however, outweighs the loss in lift thus increasing the overall performance of the configuration.

Keywords: aerodynamics, CFD, delta wing, leading edge vortices

Procedia PDF Downloads 192
2161 Steel Dust as a Coating Agent for Iron Ore Pellets at Ironmaking

Authors: M. Bahgat, H. Hanafy, H. Al-Tassan

Abstract:

Cluster formation is an essential phenomenon during direct reduction processes at shaft furnaces. Decreasing the reducing temperature to avoid this problem can cause a significant drop in throughput. In order to prevent sticking of pellets, a coating material basically inactive under the reducing conditions prevailing in the shaft furnace, should be applied to cover the outer layer of the pellets. In the present work, steel dust is used as coating material for iron ore pellets to explore dust coating effectiveness and determines the best coating conditions. Steel dust coating is applied for iron ore pellets in various concentrations. Dust slurry concentrations of 5.0-30% were used to have a coated steel dust amount of 1.0-5.0 kg per ton iron ore. Coated pellets with various concentrations were reduced isothermally in weight loss technique with simulated gas mixture to the composition of reducing gases at shaft furnaces. The influences of various coating conditions on the reduction behavior and the morphology were studied. The optimum reduced samples were comparatively applied for sticking index measurement. It was found that the optimized steel dust coating condition that achieve higher reducibility with lower sticking index was 30% steel dust slurry concentration with 3.0 kg steel dust/ton ore.

Keywords: reduction, ironmaking, steel dust, coating

Procedia PDF Downloads 273
2160 Cold Spray Coating and Its Application for High Temperature

Authors: T. S. Sidhu

Abstract:

Amongst the existing coatings methods, the cold spray is new upcoming process to deposit coatings. As from the name itself, the cold spray coating takes place at very low temperature as compare to other thermal spray coatings. In all other thermal spray coating process the partial melting of the coating powder particles takes place before deposition, but cold spray process takes place in solid state. In cold spray process, the bonding of coating power with substrate is not metallurgical as in other thermal spray processes. Due to supersonic speed and less temperature of spray particles, solid state, dense, and oxide free coatings are produced. Due to these characteristics, the cold spray coatings have been used to protect the materials against hot corrosion. In the present study, the cold spray process, cold spray fundaments, its types, and its applications for high temperatures are discussed in the light of presently available literature. In addition, the assessment of cold spray with the competitive technologies has been conferred with available literature.

Keywords: cold spray coating, hot corrosion, thermal spray coating, high-temperature materials

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2159 The Mechanical and Electrochemical Properties of DC-Electrodeposited Ni-Mn Alloy Coating with Low Internal Stress

Authors: Chun-Ying Lee, Kuan-Hui Cheng, Mei-Wen Wu

Abstract:

The nickel-manganese (Ni-Mn) alloy coating prepared from DC electrodeposition process in sulphamate bath was studied. The effects of process parameters, such as current density and electrolyte composition, on the cathodic current efficiency, microstructure, internal stress and mechanical properties were investigated. Because of its crucial effect on the application to the electroforming of microelectronic components, the development of low internal stress coating with high leveling power was emphasized. It was found that both the coating’s manganese content and the cathodic current efficiency increased with the raise in current density. In addition, the internal stress of the deposited coating showed compressive nature at low current densities while changed to tensile one at higher current densities. Moreover, the metallographic observation, X-ray diffraction measurement, transmission electron microscope (TEM) examination, and polarization curve measurement were conducted. It was found that the Ni-Mn coating consisted of nano-sized columnar grains and the maximum hardness of the coating was associated with (111) preferred orientation in the microstructure. The grain size was refined along with the increase in the manganese content of the coating, which accordingly, raised its hardness and mechanical tensile strength. In summary, the Ni-Mn coating prepared at lower current density of 1-2 A/dm2 had low internal stress, high leveling power, and better corrosion resistance.

Keywords: Ni-Mn coating, DC plating, internal stress, leveling power

Procedia PDF Downloads 338
2158 Apparent Ageing Mechanism of Polyurethane Coating in Typical Atmospheric Environment

Authors: Jin Gao, Jin Zhang, Xiaogang Li

Abstract:

Outdoor exposure experiments were conducted in three extreme environments, namely the Chinese plateau mountain environment (Lhasa), the cold–temperate environment (Mohe), and the marine atmospheric environment (Wanning), to track a new long-life environment-friendly polyurethane coating. The relationship between apparent properties, namely gloss and microstructural changes, was analyzed, and the influence of typical climatic environment on the aging mechanism of polyurethane coatings was discussed. Results show that the UV radiation in the Lhasa area causes photoaging degradation, micropores are formed on the coating surface, and the powdering phenomenon is obvious. Photodegradation occurs in the Wanning area, and a hydrolysis reaction is observed. The hydrolysis reaction catalyzes the photoaging, the coating surface becomes yellow, and the powdering becomes serious. Photoaging is also present in the Mohe area, but it is mainly due to temperature changes that in turn change the internal stress of the coating. Microcracks and bumps form on the coating surface.

Keywords: aging, atmospheric environment, outdoor exposure, polyurethane coating

Procedia PDF Downloads 92