• Journal of the Korean institute of surface engineering
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• v.51 no.1
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• pp.11-20
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• 2018

Hydrophobic and Superhydrophobic surfaces are promising technology for the surface finishing of metallic materials due to its water-repellency. Realization of highly water-repellent surface on aluminum and its alloys provides various functionalities for real application fields. In order to realize the hydrophobic/superhydrophobic surfaces on aluminum and its alloys, various technologies have been demonstrated. Especially, traditional anodic oxidation for aluminum has been widely employed for the morphological texturing of surfaces, which is essential to enhance the hydrophobic efficiency. De-wetting superhydrophobic surface on aluminum provides various exceptional properties, such as anti-corrosion, anti-/de-icing, anti-biofouling, drag reduction, self-cleaning and liquid separation. Nevertheless, the durability and stability of superhydrophobic surfaces still remain challenges for their actual applications in engineering systems and industry. In this review, the theoretical/experimental studies and current technical limitations on the hydrophobic and superhydrophobic surface using anodic oxidation of aluminum have been summarized.

• Textile Coloration and Finishing
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• v.25 no.2
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• pp.140-151
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• 2013

In order to investigate the mechanical properties of working clothes materials considering industrial settings, the test weaving materials were compared with the existing materials depending on the season. The material design of the test fabrics were changed through fineness, composition, density of materials then subsequently treated with functional finish. As a result of evaluation of the forms according to KES-FB system, Koshi was deduced, and Numeri and Fukurami were increased. Thereby, the test weaving materials became flexible, surface became smoother, elasticity and volume characteristics indicated to have been improved. Consequently, the THV value of working clothes materials for test weaving was increased compared to existing materials which indicated improved result of the total hand value. Specially, the winter cloth material indicated improved drape characteristics and dimensional characteristics, showed improved liveliness as being compressed softly.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.1
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• pp.121-128
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• 2014

Superfinishing is essential for mirror surfaces, because among mechanical components cylindrical workpieces such as spindles must maintain precision and reliability with respect to functional characteristics. However, research on standardization of polishing film application combination to obtain mirror surfaces is insufficient. Consequently, this has been a factor in rising costs of mechanical components. Therefore, in this study, experiments have been conducted to determine efficient polishing film application combination for mirror surfaces ranging from ductile materials such as SM45C, brass, aluminium 7075, and titanium to brittle materials such as $Al_20_3$, SiC, $Si_3N_4$, and $ZrO_2$. From the experimental results, efficient polishing film application combination for metallic materials and ceramic materials is confirmed.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1014-1020
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• 2003

We have developed the ultrasonic polishing system to get super finishing that consist of machine part that can rotate and travel the main shaft with power 1.5kW, ultrasonic generator with frequency 20kHz. By using this system we were investigated the characteristics of ultrasonic polishing and deduced the major facters which affect the surface roughness by the experimental plans for three different materials such as ceramic, glass, and wafer, and so could be obtained following results. We could be obtained the excellent surface for hard-to-difficult cutting materials. The rotating speed could be found to be major factor influencing the surface roughness. In the case of ceramic and wafer, we were able to obtain good surface roughness when the feed rate and ultrasonic output is higher. In the case of glass, the surface roughness becames worse when ultrasonic output is higher because of increasing of load affacting on the particles in slurry.

• Textile Coloration and Finishing
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• v.32 no.2
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• pp.73-79
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• 2020

Pursuing the fabric materials for military chemical warfare protective clothing with the improved detoxification properties, this study investigated the simple and effective cotton treatment method using pad-dry-cure process and 3-aminopropyltrimethox ysilane(APTMS) solution for surface amination. Detoxification properties of the untreated and treated cotton fabrics were evaluated via decontamination of chemical warfare agent simulant, DFP(diisopropylfluorophosphate). The surface aminated cotton fabric increased the rate of the hydrolysis of DFP by the factor of 3 and the decontamination ratio reached 88.2% after 24h. Therefore, the surface amination of the cotton fabric with APTMS can be an effective pathway to prepare the material for protective clothing against chemical warfare agents.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.21-28
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• 2014

The purpose of this study is to investigate the mechanical properties and carbonation resistance of concretes using lightweight aggregate coated surface finishing materials. To evaluate the mechanical properties and carbonation resistance of concrete, slump, air amount, air-dried unit volume weight, compressive strength, and carbonation depth are tested. In terms of the unit volume weight of concrete, air-dried unit volume weight of concrete using coating lightweight aggregate was measured as $1,739{\sim}1,806kg/m^3$. When using coating aggregate, compressive strength of concrete at 28 days was measured as much as 82.7~95.9% of the compressive strength using non-coating aggregate. It is found that compressive strength tends to decrease with coating lightweight aggregate. However, all concretes using coating lightweight aggregate except O-LWAC satisfied the criteria for 28-day compressive strength suggested in KS. The measurement of carbonation depth when the water-repellent agent was used found that carbonation depth was reduced by as much as 2.6~6.1%. On the other hand, when using polymer waterproof agent, carbonation depth was reduced by as much as 8.6~12.0%. Consequently, to improve carbonation resistance, polymer waterproof agent was more effective than water-repellent agent. In particular, epoxy showed the most outstanding performance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.186-187
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• 2019

In modern times, due to the centralized urban structure, the interval between buildings is narrow and the increase of the heat island phenomenon due to the accumulation of the structure is becoming a social problem. In order to solve these problems, various materials for reducing the surface temperature of buildings are under study. Particularly, in the case of a wall part which is a part directly affected by the outside air of the building, it is a main structural part for determining the room temperature. The purpose of this study was to develop a material that can improve the thermal environment performance of the building by evaluating the temperature control performance of the exterior finishing material using the heat reflecting material as a method for controlling the temperature of the outer wall finishing material.

• Transactions of Materials Processing
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• v.6 no.2
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• pp.95-101
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• 1997

The thermal fatigue and wear properties of high speed steel roll which was recently developed were investigated by observing microstructure, by measuring mechanical and physical properties, by conducting thermal fatigue testing, and by measuring the amount of wear in actual mill. High speed steel roll had better thermal fatigue testing, and by measuring the amount of wear in actual mill. High speed steel roll had better thermal fatigue life than high chromium iron roll, which was due to lower carbide content, higher strength, and higher thermal conductivity. The amount of wear of high speed steel roll was nearly the same as that of high chromium iron roll in the first finishing stand, which was due to the oxide formation on the roll surface. However, in the third finishing stand, the wear resistance of high speed steel roll was 2~3 times as good as that of high chromium iron roll because the former had higher hardness at high temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.604-609
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• 2020

There are various methods of finishing concrete surfaces, and when considering workability, the spray method is effective, but rebound occurs. The allocation of rebound occurrence control should be adjusted according to the materials used. Thus, a basic study was conducted on multiple techniques for reducing the rebound incidence that are suitable for surface finishing materials containing a photocatalyst. A prior study derived the reduction effect and optimal mix ratio for photocatalytic performance. Based on that study, the rebound reduction was verified according to the specifications of the content and the mechanical durability characteristics of the mixed materials. Rebound, compressive strength, flexural rigidity, and table flow tests were done. The flow was fixed at 170±10 mm considering the workability of the mortar spray equipment. For the experimental variables, the rebound number was adjusted to the silica sand variables relative to the cement weight, and silica sands No. 5 and No. 7 were used. The results show the highest compression strength in the final S-1 variable, and the amount of rebound was minimized. These results were sufficiently filled with the bindings of the silica pores, which increased the binding force between the aggregates, resulting in a lower amount of rebound.

• Textile Coloration and Finishing
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• v.23 no.4
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• pp.284-289
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• 2011

Poly(phenylene sulfide)(PPS) films were photooxidized under UV/ozone irradiation. The effect of UV energy on the surface properties of the UV-irradiation PPS films were investigated by the measurement of reflectance, surface roughness, and contact angle. Reflectance decreased at the wavelength of 400nm and the surface roughness increased with increased UV energy. The improvement in hydrophilicity with increased $O_{1s}/C_{1s}$ was caused by the introduction of hydrophilic $SO_2$ bond. Surface energy increased from 46.6 to $78.3mJ/m^2$ with increased UV energy up to $21.2J/cm^2$. Also zeta potential decreased with increased UV energy. The increased dyeability to cationic dyes may be due to the photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.he photochemically introduced anionic and dipolar dyeing sites on the PPS films surfaces.