• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2007.06a
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• pp.169-173
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• 2007

Slit-coater nozzle is one of core equipments of coating process in LCD panel manufactory. As a glass substrate size become bigger, a nozzle performance and a high-speed coating process are considered important issues. To design the optimal nozzle, the characteristics of fluid inside nozzle are studied using CFD (Computational Fluid Dynamics) method. Through research on design factors, we can know the coating uniformity influenced by lip length, cavity angle and gap size. The future work for this study is to find the factors in high-speed coating process and function between factors of design.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.254-258
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• 2009

We herein report on polymer phosphorescent light-emitting devices doped with iridium complex. The emitting layer of poly(N-vinylcabazole) and tris(2-phenylpyridine)iridium was fabricated by low speed dip-coating of 10, $20{\mu}m$/s. The devices showed stable current increasing leakage current at turn-on voltage. Compared to conventional spin-coating based organic light-emitting devices, the driving voltage by dip-coating observed lower values of 5.8 and 6.7 V at the luminance of 100 Cd/$cm^2$.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.37-37
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• 2012

The coated steels, mainly with zinc by either hot-dip galvanizing or electroplating, are widely used for panels of automotive, electrical appliances and construction, whose size of world market have reached 130 million tons in 2008. Current issues for the coated steels can be integrated in terms of high functionality, low cost, environment-friend and available resource. The best solution can be provided if thin layer coating with higher quality is produced by an eco-friendly process, and PVD, physical vapor deposition, can be an alternative practice to existing coating processes. PVD technologies have been very common ones in electronic and semiconductor industries, but recognized as non-profitable processes for the coated steels due to low process speed and lack of continuous operation skills. Systematic researches from 1990s in Europe, even though discouraged by a shutdown of the first Japanese PVD coating plant in 1999, have realized several continuous PVD coating plants, and also enhanced launching of developments in steel industries. To be successful with PVD coating technologies over existing ones, productivity to meet economics should be created from a highly sophisticated process. Some PVD technologies fit for the high-speed process will be introduced together with experiences from industrial applications.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.57-68
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• 1993

Air Wiping technique is widely used because of easy and efficient coating control in present CGL. Coaring weight is decided by nozzle header pressure, strip line speed and distance between strip and nozzle. Coating defects are results from unbalance of these factors and coating equipment calibration inaccuracy. Therefore, this study is mainly dealing with the cause of coating defects such as edge overcoating and coating deviation. The coptimum working condition is suggested by formulated coating model using collected working data. We developed two demension analysis program for air flow in nozzle and calculated dynamic pressure and air velocity with this program. The productivity and coating guality are improved by applying the result of this reserach.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.2
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• pp.192-199
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• 2002

In continuous galvanizing process, the mass of zinc deposited and its distribution are controlled by the air pressure, effective distance from the air knife nozzle to the steel strip surface and line speed. Coating defects are resulted from the unbalance of these control factors and the inaccuracy of coating equipments. This paper investigates the main cause of coating deviation and a new air knife system for control of coating thickness was developed. We investigate dynamic pressure variation by air knife types. It is found that the coating deviation is caused by the unbalance of dynamic pressure, the irregularity of strip position, and the strip vibration. Formulating a useful coating model by using present working condition, an optimal working condition is suggested. The productivity and coating quality are improved by applying the result of this research at the shop floor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.89-94
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• 2003

Hard coatings are known to improve the performance of cutting tools in aggressive machining applications, such as high speed machining. New superhard Ti-Al-Si-W films, characterized by a nanocomposite nano-sized (Ti,Al,Si)N crystallites embedded in amorphous $Si_3 N_4$ matrix, could be successfully synthesized on WC-Co substrates by a hybrid coating system of arc ion plating(AIP) and sputtering method. The hardness of Ti-Al-Si-N film increased with incorporation of Si, and had the maximum value ~50 GPa at the Si content of 9 at.%, respectively. And the X-ray diffraction patterns of Ti-Al-Si-N films with various Si content is investigated. In this study, Ti-Al-Si-N coatings were applied to end-mill tools made of WC-Co material by a hybrid coating system. Cutting tests fir the high-hardened material (STD11,$H_R$)C62 and their performances in high speed cutting conditions were studied. Also, the tool wear and tool lift of Ti-Al-Si-N with various si(6, 9, 19) contents were measured.

• Journal of Drive and Control
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• v.11 no.4
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• pp.25-31
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• 2014

This paper details application of a DLC(Diamond Like Carbon)-coating to the swash plate and the ball joint of pistons that make sliding contact with the piston shoes of an axial piston pump. This process, aimed to reduce the frictional and leakage power losses of the hydrostatic piston shoe bearings at the low speed range. At lower speeds than 100rpm, the positive effects of the DLC-coating on the power loss reduction of the hydrostatic piston shoe bearings could be confirmed. These effects resulted in little improvement in volumetric efficiency of the test pump, but the mechanical efficiency could be raised by up to 5% at 100rpm; here, the DLC-coated swash plate played a more dominant role than the DLC-coated ball joint.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.584-588
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• 2013

Studies are using a roll forming bar. A bar coating device available for a variety of coating conditions was developed. It is characterized by the bar forward and reverse rotation, fine-tune coating speed, and stripe coating. To determine the characteristics of the equipment, the coating tests under different coating conditions were carried out. As a result of the coating tests, the equipment was confirmed as one of strong candidates for the production tool of organic solar cells. The further production test of organic solar cells through stripe coating is in progress.

• Journal of Ocean Engineering and Technology
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• v.15 no.4
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• pp.60-65
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• 2001

Thermal spray coating is formed by a process in which melted particles flying with high speed towards substrate, then crash and spread on the substrate surface cooled and solidified in a very short time, Stacking of the particles makes coating. In this study, the exfoliation of $Al_2$O$_3$ and Ni-4.5wt.%Al thermally sprayed coating which were deposited by an atmospheric plasma spray apparatus are investigated using an AE method. A tensile test is conducted on notch specimens in a stress range below the elastic limit of substrate. The wave forms of AE generated from the three coating specimens can be classified by FFT analysis into two types which low frequency(type I waveform is considered to corresponds exfoliation of coating layers and type II waveform corresponds the plastic deformation of notch tip or the resultant fracture of coating. The fracture of the coating layers can estimate by AE event and amplitude, because AE features increase when the deformation generates.

• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.62-69
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• 1995

In order to investigate the effect of TiN coating on corrosion fatigue behavior of metal, the rotary bending corrosion fatigue tests were carried out in 3% NaCl solution by using the round bar specimens of high-speed steel, SKH-9, coated with TiN by PVD method. From the experimental results, fatigue strength of TiN coating steel in air was obvious improvement as compared with that of the substrate because of the restriction of dislocation movement in near surface of the substrate by hard thin film. In 3% NaCl solution, corrosion fatigue life of TiN coating specimen in high stress level was improvement same as in air. But in low stress level, corrosion fatigue life of TiN coating one was equivalent to that without coating, due to much crack initiated from corrosion pits formed at the substrate by failure of coating layer.