• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.228-230
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• 2003

Recently, lots of joining methods of thin metal sheets are being developed in order to improve joint quality and productivity in manufacturing area. Current existing welding methods are continuously challenged as new materials and smaller thickness of metal sheets are required. In this study, laser plug brazing process was investigated as a new joining method of thin metal sheets. A CO2 laser system with automatic feeding of filler metal wire and flux was developed, and laser plug brazing experiments were conducted. The brazed joints were analyzed using various methods.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2007년 추계학술발표대회 개요집
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• pp.310-312
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• 2007

Two metal cored composite wires were manufactured to satisfy AWS F7A4-EC-G specification. They were used to weld EH36 grade steels with three different fluxes. Variation of carbon, manganese, silicon, titanium, and boron contents which affect the weld metal strength in weld metal was investigated.

• 대한기계학회논문집A
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• 제33권4호
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• pp.353-359
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• 2009

Wire-woven Bulk Kagome (WBK) is a new truss type cellular metal fabricated by systematic assembling of helical wires in six directions. In this work, the experiments of mechanical behaviors of WBK cored sandwich panels subjected to bending load were performed and the results were compared with those by the corresponding analytic solutions. And also, finite element simulations were performed to validate the optimal design according to the analytic solutions. It is found the sandwich panel with WBK core performed excellently in terms of energy absorption and deformation stability after the peak point as well as the load capacity.

• 한국분말재료학회지
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• 제14권6호
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• pp.391-398
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• 2007

The surface roughness of Al, Ag and Ni nano-powders which were prepared by pulsed wire evaporation method was quantified based upon the fractal theory. The surface fractal dimensions of metal nano-powders were determined from the linear relationship between In $V/V_{mono}$ and Inln ($P^o/P$) using multi-layer gas adsorption theory. Moreover, the fractal surface image was realized by computer simulation. The relationship between preparation condition and surface characteristics of metal nano-powders was discussed in detail.

• Journal of Welding and Joining
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• 제17권1호
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• pp.116-123
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• 1999

The $CO_2$ welding with 100% $CO_2$ shielding gas is commonly used because of its cost and efficiency. Arc phenomena of the $CO_2$ welding is influenced by various factors such as chemical compositions of welding wire, shielding gas, welding condition and welding power source etc. In this study, arc phenomena is investigated by using two type of FCW(titania type, semi-metal type). Then, the welding quality and optimum welding condition can be selected. From this study, the following results were obtained; 1) In low current range(140A), FCW up to welding voltage(22V) resulted in a typical short circuit transfer. 2) In high current range(320A), the arc stability in titania FCW of a typical globular transfer is better than that of semi-metal FCW.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
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• pp.133-137
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• 2002

In this paper, the $CF_{4}$ decomposition rate are investigated for a simulated three plasma reactors which are metal particle reactor, spiral wire reactor and reactor with porous dielectric as applied voltage. The $CF_{4}$ decomposition rate by plasma reactor with porous dielectric had a gain of 20~25[%] over that by plasma reactor with spiral wire or metal particle electrode. The $CF_{4}$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_{4}$ decomposition efficiency of metal particle reactor was about 80[%] at AC 24[kV]. However, decomposition efficiency is more than 90% in case of the reactor with porous dielectric. we think, the reactor with porous dielectric should be much better than other reactors for $CF_{4}$ decomposition.

• 대한치과보철학회지
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• 제34권2호
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• pp.363-372
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• 1996

A common site of fracture in maxillary complete denture is on the anteroposterior midline that coincides with the notch for relief of the labial frenum. Various approaches to reduce the incidence of this type of fracture have been suggested. The most widely used technique is the reinforcement of acrylic resin denture base with several solid metal forms. But few comparative studies on the efficacy of metal reinforcements have been reported. This study was conducted to compare reinforcing effects of commonly available metal reinforcements, which include wire, metal mesh embedded in the denture base and metal plate affixed to the impression surface of denture base by silicoating technique. This was load on the posterior. The strain gauges were oriented perpendicular to the anteroposterior midline of maxillary polished denture surface at one labial and the four palatal sites Non-renforced denture was used as control. The results were as follows : 1. In the non-reinforced denture group, only tensile strains on the palatal polished surface were observed. The tensile strains decreased in the order of incisive papilla, posterior denture border area, mid palatal area and rugae area. Compressive strain was observed on the labial polished surface. 2. As compared with the non-reinforced denture group, the metal plate or the metal mesh reinforced denture groups showed reduced palatal tensile strains,and the metal mesh reinforcement had a better reinforcing effect than the metal plate. But both reinforced denture groups showed no difference in the amount of compressive strain on the labial polished surface when compared to the non-reinforced denture group. 3. The metal wire positioned just above the labial notch decreased the compressive strain on the labial polished surface. But the presence of metal wires in the palatal polished surface caused increase in tensile strains in the area.

• 대한치과교정학회지
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• 제37권5호
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• pp.341-350
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• 2007

본 실험은 마찰력을 줄이고 물리적 성질을 개선하여 최근에 개발된 수 종의 심미 브라켓들과 교정 탄선간에 발생하는 마찰력의 크기를 측정, 비교해 보고자 하였다. 일반 슬롯의 세라믹 브라켓인 Inspire, Signature III와 Cristaline V, 스테인레스 스틸 (SS) 슬롯을 가진 세라믹 브라켓인 Clarity, 골드 슬롯을 가진 Luxi II, polyoxymethylene 계열의 플라스틱 브라켓인 Brillant, SS 슬롯을 가진 컴파짓 브라켓인 Spirit MB, 금속 브라켓인 Integra를 사용하여 018"원형의 교정 탄선에 $0^{\circ}$, $4^{\circ}$, $8^{\circ}$의 tip angulation을 부여하고 elastic module로 결찰한 뒤 인공 타액 상태에서 활주이동 할 때의 운동 마찰력을 측정하였다. 연구 결과 슬롯에 silica 처리된 세라믹 브라켓 (CR)이 유의하게 낮은 마찰력을 보였고 (p < 0.05), 단결정 세라믹 브라켓이 (IN) 유의하게 큰 마찰력을 보였다 (p < 0.05). 플라스틱 브라켓인 polyoxymethylene 계열의 BR이 낮은 마찰력 양상을 보였고 이는 금속 브라켓과 유사하였다. 모든 브라켓에서 브라켓-탄선 각도가 증가함에 따라 유의하게 마찰력이 증가하였으나 주사전자현미경상에서 탄선이나 브라켓에 손상은 발견되지 않았다. 마찰력의 양상이 브라켓의 재질로 추측할 수 있는 것과는 다르게 나타난 결과로 보건대 심미 브라켓이 스테인레스 스틸 브라켓에 비해 마찰력 면에서는 오히려 우수하거나 큰 차이가 없으므로 임상적으로는 마찰력은 크게 고려하지 않아도 되겠다.

• Journal of Welding and Joining
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• 제18권3호
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• pp.83-88
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• 2000

Laser cladding processing allows rapid transfer of heat to the material being processed with minimum conduction into base metal, resulting in low total heat input. The effects of Nd:YAG laser cladding with wire feeding on the mechanical properties of Inconel alloy were investigated. inconel alloy is used as the material of nuclear steam generator tubing because of its mechanical properties and corrosion resistance properties. The device for Nd:YAG laser cladding with wire feeding was designed. It consists of the wire feeding system, the wire cladding system and the shielding gas system which prevents the clad layer from being oxidized. Experimental as results indicated that the wire feeding direction and position were important for laser cladding with wire feeding. The wire feeding speed should be adapted according to cladding speed for good shaping of clad layer. The effect of heat on the HAZ size can be limited and the growth of grain size of HAZ size was not serious. The hardness of clad layer and heat affected zone increased with increasing of cladding speed.

• 마이크로전자및패키징학회지
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• 제24권2호
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• pp.29-35
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• 2017

본 논문에서는 서브 밀리미터 직경의 카테터 표면 위에 금속 마이크로 와이어를 접착하는 공정을 연구하였다. 최근 유연 전자 디바이스 분야는 유연한 평면 폴리머 기판과 그 기판 위의 마이크로 전극 공정이 계속해서 연구되고 있다. 하지만, 의료 분야에서는 카테터와 같이 곡면을 가진 기판이 중요하다. 특히 카테터 중에서도 여러 한계점을 가진 뇌혈관 수술을 개선하기 위한 서브 밀리미터의 직경을 가진 조향 가능한 카테터의 중요성이 대두되고 있다. 이러한 카테터를 구현하기 위해 조향을 위한 엑추에이터들은 연구가 되고 있지만 이를 구동하기 위한 배선 연구는 진행된 바가 없다. 그러므로 본 연구에서는 이러한 서브 밀리미터 카테터 위에 마이크로 금속 와이어를 접착하는 공정을 개발하였다. 적합한 지그를 설계함으로써 마이크로 와이어를 서브 밀리미터 직경의 카테터에 정렬한다. 그리고 자외선 경화 시스템과 상용품을 이용하여 공정 시간 및 공정 비용을 감소시켰다. 상용품으로 골드 마이크로 와이어, 자외선 경화 에폭시, 자외선 램프 그리고 서브 밀리미터 카테터를 이용하였다. 공정 후 카테터는 광학 현미경, 저항 측정기, 만능 시험기를 통해 분석하였다.