• Journal of Ocean Engineering and Technology
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• v.25 no.1
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• pp.44-48
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• 2011

Researchers suggested painted coating characteristics of aluminum sheet by various sending condition. Painted coating is used to protect the surface of the blocks from the interior and exterior. It is also used to enhance the value of automobiles and ship materials. This process makes the materials surface for protection and elegance. Although analysis of the roughness and critical scratch load of painted coating is important, the effects of this material have not progressed much. In this study, the characteristics of painted coating in the other conditions of the polished aluminum sheet were investigated. The results of both various conditions and initial roughness values were almost similar to final values after painted coating.

• Journal of the Korean institute of surface engineering
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• v.28 no.5
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• pp.289-299
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• 1995

The effects of phosphate coating have been studied on physical properties and corrosion resistance of painted aluminum alloy sheet for automobile body. The physical properties (surface roughness, paint adhesion, impact resistance and pencil hardness) and corrosion resistance(cyclic corrosion and filiform corrosion) were investigated. Phosphate coatings enhanced the physical properties of painted Al alloy sheet, especially paint adhesion after the 240hours water immersion test. Phosphate coating also markedly improved the resistance for cyclic corrosion and filiform corrosion of painted cold rolled steel and Zn-Ni plated steel sheet as well as painted Al alloy sheet. The corrosion resistance of painted Al sheets was varied with the concentration of free fluoride ion and metal additives like Ni and Mn in the phosphating bath. A maximum corrosion resistance was obtained at about 300ppm of fluoride ion and additives of Ni and Mn obviously increased the corrosion resistance of painted specimens.

• Journal of Adhesion and Interface
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• v.12 no.1
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• pp.34-42
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• 2011

The roll coating process is well-known for completely replacement coating system with an existing wet paint process for automotive which has low productivity and is not environment-friendly process. It is very important to evaluate the curing behavior, corrosion resistance and processing property as well as rheological behavior in order to realize a film flexibility and hardness simultaneously. In this study, we have synthesized the polyester resin modified with hydroxyl values and molecular weight to apply the pre-painted system, and then evaluated the curing behavior, deep drawing, tensile strength and rheological properties. It was observed that N-0375-40 of 40 (mg KOH/mol) hydroxyl values showed the most suitable for flexibility, film hardness, and curing behavior.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.1037-1044
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• 2007

Metallic paint is one of the most widely used coating in automotive, cosmetic and other applications because of its well-known ability to give a product realistic look which creates widespread consumer appeal. But, this coating has complicated subsurface structure which includes pigments, flakes, and transparent clearcoat. Though various analytic reflection models are available to simulate appearance of various surfaces, it is difficult to select an appropriate reflection model with faithful parameters for simulating this coating due to the complex subsurface structure of metallic paints. This paper presents a framework for accurate modeling of metallic coating by determining an appropriate reflection model among various existing BRDF (Bidirectional Reflectance Distribution Function) models. The selection of the appropriate model is achieved by measuring BRDF of various metallic paint samples using a BRDF measuring device i.e. gonioreflectometer and fitting an existing model to the measured data. Then, this model is effectively realized by rendering metallic painted surfaces. We believe that this framework can serve as a guide for those who wants to render metallic painted surfaces accurately with analytic BRDF model without expending time on extracting BRDF data using gonioreflectometer from real metallic paint sample.

• Journal of the Korean institute of surface engineering
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• v.49 no.1
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• pp.32-39
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• 2016

In this study, Al and Zn arc thermal spray coatings were carried out onto the substrate of SS400 steel to improve corrosion resistance and durability of hull structural steel for ship in marine environment. Therefore cavitation-erosion test was conducted to evaluate the durability of painted and thermal spray coated specimens. And then the damaged surface morphology and weight loss were obtained to compare with each other, respectively. As a result, the painted specimen was the poorest cavitation resistance characteristics because surface damage behavior appeared to be exfoliated in bulk shape during the cavitation experiment. And Zn thermal spray coating layer presented the significant surface damage depth due to relatively low surface hardness and local cavitation damage tendency. On the other hand, as a result of the weight loss analysis, the painting layer presented the poorest cavitation resistance and the Al thermal spray coating layer relatively showed the best results after cavitation experiment.

• Corrosion Science and Technology
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• v.9 no.4
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• pp.153-158
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• 2010

Electrical appliances such as audiovisual equipment and personal computers have recently had heat and electromagnetic problems. In order to solve those problems, 'High heat absorbing pre-painted steel sheet (hereinafter referred to as PSS)', 'High electromagnetic shielding PSS' and 'High heat absorbing and high electromagnetic shielding PSS' have been developed. In this paper, the heat characteristics and electromagnetic shielding properties of PSS are investigated by methods that use enclosures and their mechanisms are discussed. It was found that 'High heat absorbing PSS' and 'High heat absorbing and high electromagnetic shielding PSS'could reduce the heat problem. The mechanism of the heat characteristics was presumed for the high heat absorptivity of the back coating inside the enclosure. And it was also found that 'High electromagnetic shielding PSS' and 'High heat absorbing and high electromagnetic shielding PSS' could shield electromagnetic waves well. The mechanism of the electromagnetic shielding properties was considered for the low transfer impedance of the back coating inside the enclosure. 'High heat absorbing PSS' and 'High electromagnetic shielding PSS' have been adopted as materials for electrical appliances and 'High electromagnetic shielding and high heat absorbing PSS' have been tested for that purpose.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.45-45
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• 2014

The importance of magnesium alloys has significantly increased due to their low density, high strength/weight ratio, very good electromagnetic shielding features and good recyclability. However, unfortunately, Mg alloys are very susceptible to corrosion due to their high chemically activities (= -2.356 V vs. NHE at $25^{\circ}C$), hence, most commercial Mg alloys require corrosion protective coatings. Organic coating such as painting, powder coating and electrophoretic deposition of paint (E-paint) is typically used in the final stages of the coating process of Mg alloys. In this study, effect of pre-immersion time on the deposition of E-paint on AZ31 Mg alloy was investigated. It was found that during pre-immersion time, AZ31 Mg alloy rapidly reacts with E-paint solution and paint can be self-deposited on the AZ31 surface without applying of electric current. The pore size on the E-painted AZ31 Mg alloy increased with increasing pre-immersion time from 0 to 5 min. Both adhesion and corrosion resistance of E-painted AZ31 Mg alloy decreased with increasing pre-immersion time. The best E-paint AZ31 Mg alloy, which showed stronger adhesion after water immersion test and good corrosion resistance, was started to deposit after 5 s of pre-immersion time.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.679-684
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• 2002

In this study we performed test to compare and analyze the chloride diffusion properties in concrete according to organic coating materials used at concrete structures widely and inorganic coating materials as eco-materials in recently. The results of study were shown as follow ; 1) Chloride diffusion coefficient was low as low as and that of organic and inorganic painted was lower than non-painting 2) In case of inorganic coating material applied in this study, it should be possible to evaluate the chloride diffusion properties by CTH method. Because presumption value by CTH method is similar with real estimate value by digestion experiment.

• Journal of the Korean institute of surface engineering
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• v.49 no.5
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• pp.395-400
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• 2016

This article reports improved corrosion resistance and adhesion of electro-paint (E-paint) with fluoride conversion coating (FCC) on AZ31 Mg alloy for the first time. These improvements were observed in comparison to chemically polished samples with no chemical conversion coating and samples with cerium conversion coatings (CeCC). FCCs were prepared in a hydrofluoric acid (HF) solution for four different times; 10, 30, 60, and 120 s. The colour of the samples changed from light gold to brown with increasing immersion time, indicating the formation of thicker FCC coatings with increasing immersion time. The adhesion of the E-paint on FCC-coated AZ31 Mg alloy was tested after 500 h of immersion in deionized (DI) water. Salt spray test (SST) results revealed delamination of E-paint on the chemically polished sample, severe blistering on the samples with CeCC, but no delamination and no blistering on the samples with FCC.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.189-189
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• 2015

In this study, the corrosion resistance and adhesion of electrophoretic paint (E-paint) were studied on AZ31 magnesium alloy pretreated in cerium chemical conversion coating solutions with the addition of various ethanol concentrations. It was found that with increasing ethanol concentration from 0 to 90 percent can decrease the formation of $Mg(OH)_2/MgO$ and increase the formation of nano-crystalline cerium oxides on the coating. Both corrosion resistance and adhesion of E-painted AZ31 increased with increasing ethanol concentration. The best E-paint sample was observed on the sample pretreatment in cerium chemical conversion coating solution with the addition of 80 percent of ethanol. This sample showed an excellent adhesion without paint detached after water immersion test for 500 h at $40^{\circ}C$, and only a few blisters observed at the near scratched sites after 1000 h salt-spray test.