• 반도체디스플레이기술학회지
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• 제5권3호
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• pp.33-36
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• 2006

To produce a fine structure with uniform surface of barrier ribs in PDP, acid etching process has been used in manufacture process. It is necessary to understand the mechanism of etching, particularly on the interface of ceramic fillers and matrix glass. We investigated the effect of ceramic fillers (ZnO, $Al_2O_3$) on the microstructure of borate glass system to find an etching mechanism of barrier ribs. The barrier ribs was etched with several steps, dissolving a small amount of residual glass, taking out alumina fillers, and removing a cluster type of ZnO fillers and glass matrix.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.94-103
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• 2002

Accurately controlling the shape of the read/write head structure is critical in the performance of a modern hard disk drive. The sliders investigated are composed of alumina and titanium carbide (AlTiC) and act as an air bearing when passing over the disks. Controlling the curvature of the slider is of primary importance. A laser scribing system that produces curvature by Inducing residual stress into the slider can be utilized. Predicting the curvature created by a pattern of scribes is of great importance to increase the control over the sliders' shape. Using finite element analysis a force system that produces stresses similar to the laser scribing is applied. The curvatures created by the force system are calibrated to experimental measurements.

• 대한기계학회논문집
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• 제14권3호
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• pp.547-553
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• 1990

본 연구에서는 알루미나 세라믹(Al$_{2}$O$_{3}$)재료와 순수구리를 티타늄 용자재로써 접합한 브레이징 접합물내의 냉각후 잔류응력을 유한요소법으로 사용하여 해석하였다.

• Journal of Welding and Joining
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• 제34권6호
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• pp.20-27
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• 2016

This study deals with the proper conditions of the trail rolling method (TRM) for the prevention of the buckling welding distortion at the AA5083 GMA butt weldment. For it, the effect of the working conditions of TRM including the rolling depth and the rolling distance between the welding torch and the roller on the longitudinal welding shrinkage force of the weldment was evaluated by using 3 dimensional thermo-mechanical FE analyses. The longitudinal welding shrinkage force inducing the buckling welding distortion at the GMA butt weldment was mitigated with an increase in the rolling depth and the rolling distance between the welding torch and the roller. Based on the results, the proper conditions of trail rolling method were established to reduce the longitudinal welding shrinkage force of the GMA butt weldment to below the critical value corresponding to the bucking distortion.

• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.35-42
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• 2011

This paper describes the characteristics of high speed grinding and the influence of wheel surface speed V and a grindability of the grinding materials. The various fine ceramics pieces was ground by metal and vitrified bonded diamond wheel. The surface roughness of fine ceramics(Zirconia($ZrO_2$), Silicon Carbide(SiC), Silicon Nitride($Si_3N_4$), Alumina($Al_2O_3$)) decreases from $0.05{\mu}m(R_{max})$ to $0.025{\mu}m(R_{max})$ when the wheel speed at grinding point increases the wheel speed. Relation between the temperature at grinding point and surface roughness was linear. Abrasive jet machining(AJM), a specialized from of shot blasting, is considered one of the most helpful micro machining methods for hard and brittle materials such as glasses and ceramics by constant pressure grinding.

• Structural Engineering and Mechanics
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• 제5권6호
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• pp.755-765
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• 1997

Within the framework of anisotropic combined viscoplastic hardening formulation, accounting macroscopically for residual stress as well as texture development at finite deformations of metals, simple shear analyses for the simulation of fixed-end torsion experiments for ${\alpha}$-Fe, Al and Cu at different strain rates are reviewed with an emphasis on the role of constitutive spins. Complicated responses of the axial stresses with monotonically increasing shear deformations can be successfully described by the capacity of orthotropic hardening part, featuring tensile axial stresses either smooth or oscillatory. Temperature effect on the responses of axial stresses for Cu is investigated in relation to the distortion and orientation of yield surface. The flexibility of this combined hardening model in the simulation of finite inelastic strains is discussed with reference to the variations of constitutive spins depending upon strain rates and temperatures.

• E2M - 전기 전자와 첨단 소재
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• 제7권5호
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• pp.409-416
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• 1994

A double layered photoreceptor using phthalocyanine dye was made by dip-coating method. The under cutting layer(UCL) was coated with A1$\_$2/O$\_$3/ or polyamide, and the charge generation layer(CGL) was formed by .tau.-type metal-free phthalocyanine. The oxadiazole was used as a charge transport layer(CTL) and polycarbonate and poly(vinyl butyral) was employed as a host polymer. The .tau.-H$\_$2/Pc had an absorption peak around 780nm, which coincided with the emitting wavelengths of GaAlAs diode lasers. Maximum charge acceptance of CTL that gives thickness of 12.mu.m was -900V by corona charge of -6.0kV. In photo-induced discharge measurements, residual potential was less than -20V and sufficient for ordinary use, and sample films using of poly(vinyl butyral) was showed good charge retention. In printing test, drum that was employed polycarbonate as a host polymer showed the good print quality.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.298-302
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• 2011

티타늄 용접부는 수소취성과 잔류응력에 대한 영향을 최소화 하기 위해 용접 후 잔류응력 제거 열처리 작업을 수행하고 있다. 하지만, 현재 항공 분야에 널리 사용하고 있는 규격에 따라 열처리 온도가 다양하게 설정되어 있어 현장에 적용하기에는 어려움이 있다. 이에 규격 별로 대표하고 있는 열처리 조건을 선정하여 열처리 조건에 따른 용접부에 대한 잔류응력, 잔류수소량을 확인하였고, 용접부에 대한 강도와 충격 인성을 확인하였다.

• 자원리싸이클링
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• 제15권5호
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• pp.26-32
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• 2006

LCD와 반도체 제조공정에서 발생하는 인산, 질산, 초산, Al, Mo 등이 혼재하고 있는 인산계 혼산폐액을 액정제조공정에서 사용할 수 있는 고순도 에칭액으로 재활용하기 위해서 용매추출법, 진공증발법, 확산투석법 및 이온교환법의 각각의 기술적 특성을 살린 혼합 처리공정을 이용하여 고순도 인산회수 기술을 확립하고 상용화 시스템을 개발하고자 하였다. 시험 결과 진공증발에 의해 질산과 초산을 100% 제거할 수 있었고, TOP를 이용한 용매추출에서도 추출 4단, 탈거 6단으로 완벽하게 제거할 수 있었다. 이온교환의 전단계로 적용한 확산투석에서 Al 97.5%, Mo 36.7% 제거할 수 있었고 이온교환공정에서 Al 및 Mo를 각각 1ppm이하로 정제할 수 있었다.

• 상하수도학회지
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• 제19권4호
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• pp.487-496
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• 2005

Chlorine bulk decay tests were carried out by bottle test under controlled conditions in a laboratory. Experiments were performed at different temperatures: $5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and the water temperatures when samples were taken from the effluent just before entering to its distribution system. 38 bulk tests were performed for water of Al (water treatment plant), 4 bulk tests for A2 (large service reservoir), and A3(pumping station). Residual chlorine concentrations in the amber bottles were measured over time till about 100 hours and bulk decay coefficients were evaluated by assuming first-order, parallel first-order, second-order. and $n^{th}-order$ reaction. The $n^{th}-order$ coefficients were obtained using Fourth-order Runge-Kutta Method. A good-fit by the average coefficient of determination ($R^2$) was first-order ($R^2=0.90$) < parallel first-order ($R^2{_{fast}}=0.92$, $R^2{_{slow}}=0.95$) < second-order ($R^2=0.95$) < $n^{th}-order$ ($R^2=0.99$). But if fast reaction of parallel first-order bulk decay were applied to the effluent of large service reservoir with ca. 20 hours of travel time and slow reaction in the water distribution system following the first 20 hours, parallel first-order bulk decay would be best and easy for application of water quality modeling technique.