• Journal of Welding and Joining
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• 제24권1호
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• pp.43-49
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• 2006

This paper describes the friction surface modification which has been successfully developed with the friction stir welding recently There are several problems including just position control and backlash in conventional friction surface modification system. Therefore it has been developed the friction surface modification system which has been controlled precisely both position and force by driving hydraulic cylinder in this paper. The mechtrode rotation speed(N) and feeding speed(Vz), travel speed(Vx,y) are of critical importance for the width and thickness of the coating in friction surfacing process. But there is no theoretical method of determining interrelations between process parameters affect the coating width and thickness. As a result of DOE(design of experiment) with developed system, the coating thickness and width seemed to decrease according to increase the mechtrode rotation speed(N) and traveling speed(Vx,y), to decrease feeding speed(Vz) apparently. However as the result of regression analysis the main effect was only the mechtrode rotation speed in the coating thickness.

• 센서학회지
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• 제25권1호
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• pp.35-40
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• 2016

Pulse diagnosis is one of the representative diagnostic methods in Oriental medicine. In this study, a pulse pressure sensor array coated with silicone, which includes 6 piezo-resistive sensors and 1 thermistor, is fabricated for pulse measurement. It is necessary to coat the pulse sensor array with silicone to avoid the fracture or damage of pressure sensors when the sensor is in contact with the skin and a constant pressure is applied. However, the silicone coating on the pulse sensor array can cause signal interference among the sensors in the pulse sensor array. The interference number (IN), a calculation for expressing the degree of interference among channels, is changed according to the silicone thickness on the pulse sensor array. The IN is increased by a thick silicone coating, but the fabrication error, an important index for the mass production of the sensor array, is reduced by the thickness of the silicone coating. We propose that the thickness of the silicone on the pulse sensor array is an important consideration for the performance of the fabricated sensor and manufacturing repeatability.

• 대한조선학회논문집
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• 제47권5호
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• pp.743-749
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• 2010

Multi-nozzle spray painting procedure of the inorganic zinc shop primer was established in order to obtain uniform film thickness. The shop primer paint prevents the corrosion of steel block during shipbuilding. When the dry film thickness of shop primer is insufficient, rust will be generated on the steel block. Otherwise, thick coating of shop primer may be a problem of weld defect. So, it is important to obtain the uniform film thickness of shop primer. The uniformity of dry film thickness is affected by spray speed, distance from spray gun to target surface and overlapping span of spray path. In order to uniformly maintain coating thickness of shop primer, the coating procedure was established based on the correlation of shop primer spray variables.

• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.7-13
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• 2011

In Korea, the car mobile phone service had started in 1961 and with this Korea Mobile Telecommunications Services was established in 1984. Its service was mainly focused on the mobile phone service for the car which led the popularity of the full-scale mobile phone service. There are many kinds of materials, colors and patterns which are the elements of surface coating techniques. In light of that, we are focused on the UV coating that is ranked as an important part of the techniques in this study. In the first, the use of various materials for the cellular phone and surface processing techniques for the cellular phone were searched. On the basis of the results, the experiments of actual consumer experience with the exfoliation of the surface were done and through that we proposed the best way of processing the surface for the cellular phone and the materials. The result of the Wear Test showed that thick coating was detached more slowly and each company differed in their results with UV paints despite the same thickness of UV coating. The seal (UV) exfoliation of cellular phone is deeply related with the film thickness and the film formation when the users use the cellular phones and the exfoliation of the cellular phone surface will be decreased if the manufacturers meet the best conditions for the cellular phone.

• 열처리공학회지
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• 제35권5호
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• pp.262-269
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• 2022

In order to process materials such as engineering plastics, which are difficult to mold due to their high strength compared to conventional polymer materials, it is necessary to improve the hardness and strength of parts such as screws and barrels of injection equipment in extrusion system. High-velocity oxygen fuel (HVOF) process is well known for its contribution on enhancement of surface properties. Thus in this study, using the HVOF process, WC coating layers of different thicknesses were bonded to the surface of S30C substrate by controlling the movement speed of the spray nozzle and each property was evaluated to decide the optimization condition. Through the results, the thickness of WC coating layer increased from 0 to 200 ㎛ maximum, along with the decrement of nozzle movement speed and the surface hardness get increased. Especially, the coated layer with the thickness over 180 ㎛ under the nozzle speed 500 mm/s had high hardness than thinner layer. In addition, the amount of wear consumed per unit time was also significantly reduced due to the formation of the coating layer.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4112-4112
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• 2001

The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

• 한국재료학회지
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• 제10권4호
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• pp.264-269
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• 2000

$TiO_2$sol(30wt%, anatase)을 이용하여 스핀코팅으로 유리기판에 $TiO_2$박막을 제조하였다. 박막의 두께는 코팅주기의 횟수가 조절하였다. 한 코팅주기는 스핀코팅, 건조, 열처리를 포함한다. 박막의 반응성은 막 위에서의 자외선강도가 0.44와 2.mW/$\textrm{cm}^2$인 조건에서 벤젠기체의 광분해 속도를 통해 조사하였다. 박막의 두께가 증가할수록 표면적으로 증가로 인해 반응성은 증가하였으며, 0.44mW/$\textrm{cm}^2$일 때 4$\mu\textrm{m}$정도 이상의 두께에서 반응성은 더 이상 증가되지 않았다. porous한 $TiO_2$박막은 비교적 넓은 유효표면적을 가지고 있으며, 그것은 비교적 높은 자외선 강도하에서 박막두께에 따라 반응속도를 증가시키는 결과를 낳았다.

• 한국세라믹학회지
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• 제51권6호
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• pp.533-538
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• 2014

Today, silicon and epoxy resin are used as materials of conversion lenses for white LEDs on the basis of their good bonding and transparency in LED packages. But these materials give rise to long-term performance problems such as reaction with water, yellowing transition, and shrinkage by heat. These problems are major factors underlying performance deterioration of LEDs. In this study, in order to address these problems, we fabricated a conversion lenses using glass, which has good chemical durability and is stable to heat. The fabricated conversion lenses were applied to a remote phosphor type. In this experiment, the conversion lens for white LED was coated on a glass substrate by a screen printing method using paste. The thickness of the coated conversion lens was controlled during 2 or 3 iterations of coating. The conversion lens fabricated under high heat treatment temperature and with a thin coating showed higher luminance efficiency and CCT closer to white light than fabricated lenses under low heat treatment temperature or a thick coating. The conversion lens with $32{\mu}m$ coating thickness showed the best optical properties: the measured values of the CCT, CRI, and luminance efficiency were 4468 K, 68, and 142.22 lm/w in 20 wt% glass frit, 80 wt% phosphor with sintering at $800^{\circ}C$.

• 소성∙가공
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• 제15권5호
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• pp.366-372
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• 2006

The effect of coating time in arc ion plating on surface properties of the TiN-coated high speed steel(SKH51) is presented in this paper. Surface roughness, micro-hardness, coated thickness, atomic distribution of TiN and adhesion strength are measured for various coating times. It has been shown that the coating time has a deep influence on the micro-hardness, the coated thickness, the atomic distribution of Ti and the adhesion strength of the SKH51 steels but that it has little influence on the surface roughness.

• 한국해양공학회지
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• 제17권6호
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• pp.77-82
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• 2003

The absorption of water into an anti-corrosive organic coating, such as alkyd and urethane resin coating, was investigated, using a quartz crystal microbalance (QCM). Anticorrosive properties of the coatings were also measured, by means of electrochemical impedance spectroscopy (EIS). The overall absorption of water in the coating is determined by the chemical nature of resin, and decreases with increasing thickness. The enhancement of anti-corrosive performance, through increase of coating thickness, was more remarkable in the case of the coating that hadlower equilibrium water absorption. The absorption kinetics curves were Fickian in nature. The EIS analysis confirmed that the resin, having lower equilibrium water absorption, shows higher anti-corrosive performan.