• Smart Structures and Systems
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• v.32 no.2
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• pp.123-133
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• 2023

This paper proposes a thermography-based coating thickness estimation method for steel structures using model-agnostic meta-learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured using an infrared (IR) camera. The measured heat responses are then analyzed using model-agnostic meta-learning to estimate the coating thickness, which is visualized throughout the inspection surface of the steel structure. Current coating thickness estimation methods rely on point measurement and their inspection area is limited to a single point, whereas the proposed method can inspect a larger area with higher accuracy. In contrast to previous ANN-based methods, which require a large amount of data for training and validation, the proposed method can estimate the coating thickness using only 10- pixel points for each material. In addition, the proposed model has broader applicability than previous methods, allowing it to be applied to various materials after meta-training. The performance of the proposed method was validated using laboratory-scale and field tests with different coating materials; the results demonstrated that the error of the proposed method was less than 5% when estimating coating thicknesses ranging from 40 to 500 ㎛.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.1
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• pp.33-38
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• 2007

Door guide rail is the core part which guides window when it moves up and down. But when the method of grease lubrication in the core has been used for a long times, its lubrication performance has been weakened. Therefore the method of the solid lubrication such as teflon(PTFE) coating in the rail has been studied to be increased the performance in these days. In this study the friction wear characteristic the surface with teflon coating of door guide rail for automobile has been researched. In 1, 20 Hz frequency friction wear tests the friction coefficient are below 0.188 and 0.213. In indicate test the wear depth is very slight. Therefore the durability to the friction wear in the surface with teflon coating of door guide rail is good. In addition to, the result of this study can make efficient use to a basic study to develop method of test evaluation to door guide rail surface grade. Especially this study will contribute to improve the quality of automobile parts.

• Korean Journal of Metals and Materials
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• v.48 no.8
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• pp.724-729
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• 2010

The effect of potassium permanganate ($KMnO_4$) in an electrolyte on the corrosion performance of magnesium alloy coated by micro-arc oxidation (MAO) has been investigated in this study. For this purpose, MAO coating was carried out on the present sample under AC condition in an alkaline silicate electrolyte with and without $KMnO_4$. Irrespective of the addition of $KMnO_4$, it was found from structural observation that the ceramic coating layers consisted of inner and outer layers. In the sample processed in the electrolyte with $KMnO_4$, the outer layer became dense and even contained a number of $Mn_2O_3$ atoms, resulting in high corrosion resistance. Based on the results of a potentiodynamic polarization test, it was confirmed that the coating layer formed in the electrolyte with $KMnO_4$exhibited better corrosion resistance than that without $KMnO_4$. The high corrosion resistance of the MAO-treated magnesium alloy was explained in relation to the equivalent circuit model.

• Textile Coloration and Finishing
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• v.29 no.3
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• pp.131-138
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• 2017

Most of high performance fabrics for the car racing protective clothing have been developed to have thermal resistance, flame retardant property, impact resistance and anti-frictional properties to protect the racer from the crucial accident. In this study, the meta-aramid fabric, which has inherent flame retardant, was coated with nanoparticles of SiC to enhance the impact resistance and anti-friction properties. Uniform coating of the nanoparticles onto the fabrics was obtained by using tape casting method. As the experimental parameters, size and content of the SiC nanoparticle were varied with the coating conditions of the fabric surface. The effects of the nanoparticle coating on the properties of meta-aramid fabric were examined with various instrumental analyses such as SEM, tensile strength and abrasion test.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.118-119
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• 2017

The combined waterproofing method is an excellent method to overcome the disadvantages of the single waterproofing method by composing two or more materials to complement each other, but it is a method that can cause defects such as separation and peeling between materials due to the heterogeneity of the applied two materials. In order to improve this, in this study, we aimed to develop a technology for inducing chemical unification between materials through a urea reaction with a coating material applied on the lower side by laminating a nonwoven fabric treated with a modified amine on the back surface of the sheet material, The adhesion performance test was carried out with the presence or absence of denatured amine treated nonwovens as variables. As a result of the test, it was confirmed that the adhesion performance of the specimen to which the modified amin - treated nonwoven fabric was applied was improved by about 60% or more as compared with the specimens not having the denatured amine treated specimen.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.59-64
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• 2003

Recently, as people pay attention to the environmental pollution, the emissions of diesel engine have been a serious problem. We carried out the performance evaluation test of Diesel Oxidation Catalysts (DOC) for HSDI diesel engine equipped vehicles. The DOC, basically coated with Pt catalyst, was manufactured with various washcoat materials. It was found that CO conversion efficiency depends on temperature, but THC conversion efficiency is dominated by temperature and space velocity. The THC and CO conversion efficiencies of aged catalysts were increased with additions of $ZrO_2$ and zeolite B in the washcoat. We found that DOC performance changes with coating techniques, even through it has same washcoat materials. The DOC coated by high temperature washcoat coating technology showed good conversion efficiency than low temperature washcoat coated DOC.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3233-3237
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• 2010

A $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ cathode was modified by coating with Li-La-Ti-O, and the effect of the coating thickness on their electrochemical properties was studied. The thickness of the coating on the surface of $Li[Ni_{0.3}Co_{0.4}Mn_{0.3}]O_2$ was increased by increasing the wt % of the coating material. The rate capability of the Li-La-Ti-O-coated electrode was superior to that of the pristine sample. 1- and 2-wt %-coated samples showed considerable improvement in capacity retention at high C rates. However, the rate capability of a 5-wt %-coated sample decreased. All the coated samples showed a high discharge capacity and slightly improved cyclic performance under a high cut-off voltage (4.8 V) condition. Results of a storage test confirmed that the Li-La-Ti-O coating layer was effective in suppressing the dissolution of the transition metals as it offered protection from the attack of the acidic electrolyte. In particular, the 2- and 5-wt %-coated samples showed a better protection effect than the 1-wt %-coated sample.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.104-105
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• 2013

The buildings constructed with steel structure is coated with certified fire resistive material to resist from fire. Coating materials lose their initial performances as time passes, so they need some maintenance. Fireproof spray-application also loses its performance and this performance loss of thr fireproof spray-application is very important because fire resistance of buildings depends on fireproof spray-application. So this study is to develop Acceleration durability test method of Fireproof spray-application, and use the Certification of fire resistant coating system.

• Journal of the Korean institute of surface engineering
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• v.38 no.6
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• pp.234-240
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• 2005

In this study, ion nitriding of a EHA pump part made of AISI 4340 steel was performed under different applied power conditions to study the relationship between dimensional changes of specimens and the type of applied power source. Microstructures and micohardness distribution at different processing conditions were also examined. Duplex surface treatment of ion nitriding with the optimum process conditions to produce the minimum dimensional variation in a EHA pump part and a TiN thin film coating by unbalanced magnetron sputtering was performed and the specimens with a duplex surface treatment were subjected to a high speed wear test to evaluate the wear performance of EHA hydraulic pump parts with various surface treatment conditions. Results indicated that uniform and continuous surface layer with a minimum dimensional variation could be obtained by ion nitriding with bipolar mode power source and much enhanced wear characteristics with a duplex surface treatment could be obtained, compared with results from ion nitriding or single-layerd TiN coating specimens.

• Journal of Ocean Engineering and Technology
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• v.24 no.5
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• pp.60-66
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• 2010

Zinc has a number of characteristics that make it well suited for use as a coating to protecting iron and steel products from corrosion. Its excellent corrosion resistance in most environments accounts for its successful use as a protective coating on a variety of products and in many exposure conditions. The excellent field performance of zinc coatings results from their ability to form dense, adherent films that corrode at a rate that ranges from 1% to 10% of the corrosion rate of ferrous materials, depending on the environment. Recently, EU RoHS and EU ELV prohibited the use of materials that adversely affect the environment, such as Pb, Hg, Cd, and $Cr^{+6}$. In this study, environmentally-friendly, Cr-free solutions (epoxy solution, acrylic solution, and urethane solution S-700) and organic/inorganic solution with Si; LRO-317) were used to evaluate the corrosion resistance of zinc-coated steel subjected to a saltwater spray for 72 hours. The coating of urethane solution (S-700) was best among the three kinds of solution with heat treatment during five minutes at $190^{\circ}F$. Test specimens with S-700 and LRO-317 coating were heat treated in a drying oven at 170, 180, 190, 200, and $210^{\circ}C$ for five minutes. The results show that the optimum corrosion resistance was $190^{\circ}C$ in EGI and $170^{\circ}C$ in HDGI, respectively.