• 소성∙가공
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• 제32권3호
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• pp.160-165
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• 2023

As the supply of eco-friendly vehicles increases, the application rate of hot stamping components is rising to reduce vehicle weight and improve safety. Although Al-Si coated steel sheets are commonly used in hot stamping processes, their manufacturing costs are elevated due to process patents and royalties. Various hot stamping studies have been conducted to reduce these production costs. In this study, we derived a process control method for suppressing the oxide layer of hot stamping parts using uncoated boron steel sheets. Firstly, hat-shaped parts were hot stamped under atmospheric conditions to analyze the tendency of oxide layer formation by location. Then, the Gleeble system was used to observe oxide layer formation based on oxygen content under various atmospheric conditions. Finally, the oxide layer thickness was quantitatively measured using SEM images.

• 한국전기전자재료학회논문지
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• 제21권3호
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• pp.208-212
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• 2008

This paper reports physical properties of in situ boron doped silicon films made from boron source gas and silane ($SiH_4$) gas in a conventional low-pressure chemical vapor deposition vertical furnace. If the p-type polysilicon is formed by boron implantation into undoped polysilicon, the plasma nitridation (PN) process is added on the oxide in order to suppress boron penetration that can be caused during the thermal treatments used in fabrication. In-situ boron doped polysilicon deposition can complete p-type polysilicon film with only one deposition process and need not the PN process, because there is not interdiffusion of dopant at the intermediate temperatures of the subsequent steps. Since in-situ boron doped polysilicon films have higher work function than that of n-type polysilicon and they are compatible with the underlying oxide, they may be promising materials for improving memory cell characteristics if we make its profit of these physical properties.

• 한국정밀공학회지
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• 제15권9호
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• pp.145-151
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• 1998

In this study, the experimental and analytic investigation with cold air system has been performed for improving the working environment of the conventional grinding fluid. Very simple cold air system was developed which could replace by the conventional grinding fluid system. The identification of heat of grinding Bone is very important for precision grinding. The experimental data was analysed to investigate the heat which was transferred to the workpiece. It was found that 45∼55％ of the total energy for dry grinding, 22∼28％ for wet grinding, and 32∼35％ for cold air system are conducted to the workpiece in grinding with cubic boron nitride wheel. Cubic boron nitride wheel could reduce the residual stress and thermal demage comparing with aluminium oxide wheel, because cubic boron nitride wheel has very high extreme thermal conductivity.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권2호
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• pp.103-110
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• 2001

Gate oxide scaling for sub-l00nm CMOS devices has been studied. Issues on the gate oxide scaling are reviewed, which are boron penetration, reliability, and direct tunneling leakage currents. Reliability of Sub-2.0nm oxides and the device performance degradation due to boron penetration are investigated. Especially, the effect of gate leakage currents on the transistor characteristics is studied. As a result, it is proposed that thinner oxides than previous expectations may be usable as scaling proceeds. Based on the gate oxide thickness optimization process we have established, high performance CMOS transistors of $L_{gate}=70nm$ and $T_{ox}=1.4nm$ were fabricated, which showed excellent current drives of $860\mu\textrm{A}/\mu\textrm{m}$ (NMOS) and $350\mu\textrm{A}/\mu\textrm{m}$ (PMOS) at $I_{off}=10\mu\textrm{A}/\mu\textrm{m}$ and $V_dd=1.2V$, and CV/I of 1.60ps (NMOS) and 3.32ps(PMOS).

• 접착 및 계면
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• 제19권3호
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• pp.113-117
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• 2018

보론카바이드는 하드니스가 다이아몬드나 보론 나이트라이드 보단 낮지만 30 GPa이상의 높은 경도를 갖고 있으며, 높은 경도로 인해 탱크 장갑, 탄피 제조에 사용되고 있다. 또한 중성자를 흡수하는 능력이 있어 중성자 흡수제로 많이 사용되고 있어, 핵 발전 관련 사업에 활용도가 증가하고 있다. 중성자는 전자와의 상호작용이 없으며, 물질을 통과하는 과정에서도 상호작용 없이 통과하는 것으로 알려져 있다. 보론 카바이드와 함께 중성자와 상호작용이 높은 원자는 수소이며, 보론을 포함하는 수소 농도가 높은 폴리에스터, 에폭시 고분자 등이 원자력 발전 폐기물 보관을 위한 제품 제조를 위한 소재로 사용되고 있다. 본 논문에서는 보론 카바이드의 표면을 철산화물과 텅스텐으로 처리하여, 개질된 보론 카바이드와 에폭시 소재와의 상호작용을 향상시켰다. XRD, XPS를 이용하여 표면개질 되었음을 확인하였고, 처리된 보론카바이드의 함량에 따른 기계적 강도는 만능시험기(UTM)로 측정하였으며, 동역학 분석기(DMA)를 사용하여 경화물의 동적 특성을 관찰하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.394-394
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• 2011

최근 태양전지의 후면에서 통상적으로 사용되는 Al을 이용한 후면의 BSF형성과 그에 관한 연구보다 계면의 recombination을 줄이기 위하여 passivation 특성이 좋은 층을 후면에 형성하고 국부적으로 BSF를 형성하는 back contact을 형성하여 특성을 향상시키는 연구가 많이 이루어지고 있다. 본 연구는 이러한 local back contact을 boron-BSF를 이용하여 형성하고 passivation layer는 oxide를 이용한 구조를 SILVACO 2-dimension simulation을 이용하여 그 특성을 분석하였다. Boron-local back contact 구조에서 boron-BSF의 doping concentration, depth, lateral width, boron-BSF spacing 가변을 통해 태양전지의 특성변화에 대해서 spectrum response를 통한 QE 분석 및 I-V를 분석하여 최적화하였다.

• Steel and Composite Structures
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• 제19권3호
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• pp.777-787
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• 2015

Production and properties of metal matrix composites reinforced with an in-situ high aspect ratio $AlB_2$ flake have been investigated. Boron 2.2wt.% was dissolved in pure Al and Al-Cu alloy at $1300^{\circ}C$ by adding directly boron oxide which resulted in 4 vol.% reinforcing phase. The in-situ $AlB_2$ flake concentration was increased up to 30 vol.% in order to increase the tensile strength of the composites. Hardness, compressive strength and tensile strength of the composite were measured and compared with their matrix. Results showed that 30 vol.% $AlB_2/Al$ composite show a 193% increase in the compressive strength and a 322% increase in compressive yield strength. Results also showed that ductility of composites decreases with adding $AlB_2$ reinforcements.

• 전기의세계
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• 제30권4호
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• pp.227-230
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• 1981

The variation of sheet resistance and the reduction of masking oxide thickness with the flow rate of nitrogen gas has been measured in Boron predeposition process with Planar Diffusion source, BN-975. At 900.deg. C, the sheet resistance varied as much as 75% when the nitrogen flow rate was changed from 0.4 liters/min to 2.0 liters/min. At 975.deg. C, however, only 12% of sheet resistance variation was observed under the same flow rate change. The reduction of masking oxide thickness at 975.deg. C for a 5 min predeposition was 600 nm when the nitrogen flow rate was 0.4 liters/min. When the flow rate incresased to 1.9 liters/min, however, only 100nm of masking oxide was consumed in a similar predeposition process.

• 열처리공학회지
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• 제24권1호
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• pp.37-44
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• 2011

High temperature wear of AlCrN coated tool steels sliding against the ultra-high strength boron steels used for hot press forming has been studied. The sliding wear tests have been carried out using a pin-on-disc of configuration under applied normal load of 50 N for 20 min with heating the ultra-high strength boron steels up to $800^{\circ}C$. Characterizations of tribolayers formed on the contacting surfaces between the tribopairs of the AlCrN coated tool steels and the ultra-high strength boron steels have been studied. It was found on the tribolayers of the AlCrN coated tool steels that microcracking and oxides containing Fe and Cr to increase friction coefficient were formed at the early stage of sliding wear, followed by the generation of the smeared oxide layers containing Fe transferred from the tribopair to decrease friction coefficient. This may mainly contribute to very low specific wear rate of the AlCrN coated tool steels sliding against the ultra-high strength boron steels, resulting from oxideoxide contact between the tribopair.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.668-674
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• 2017

Experimental verification of boron species in fuel CRUD (Chalk River Unidentified Deposit) would provide essential and important information about the root cause of CRUD-induced power shifts (CIPS). To date, only bonaccordite and elemental boron were reported to exist in fuel CRUD in CIPS-troubled pressurized water reactor (PWR) cores and lithium tetraborate to exist in simulated PWR fuel CRUD from some autoclave tests. We have reevaluated previous analysis of similar threadlike crystals along with examining some similar threadlike crystals from CRUD samples collected from a PWR cycle that had no indications of CIPS. These threadlike crystals have a typical [Ni]/[Fe] atomic ratio of ~2 and similar crystal morphology as the one (bonaccordite) reported previously. In addition to electron diffraction study, we have applied electron energy loss spectroscopy to determine boron content in such a crystal and found a good agreement with that of bonaccordite. Surprisingly, such crystals seem to appear also on corroded surfaces of Alloy 600 that was exposed to simulated PWR primary water with a dissolved hydrogen level of $5mL\;H_2/kg\;H_2O$, but absent when exposed under $75mL\;H_2/kg\;H_2O$ condition. It remains to be verified as to what extent and in which chemical environment this phase would be formed in PWR primary systems.