• 폴리머
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• 제36권5호
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• pp.549-554
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• 2012

난연제 triphenyl phosphate는 HDPE(high-density polyethylene)/EPDM(ethylene-propylene diene monomer)/boron carbide 내에서 miscibility가 좋지 못하여 고분자의 기계적 물성을 크게 저하시킨다. HDPE/EPDM/boron carbide/triphenyl phosphate 블렌드의 분산성을 향상시키기 위해서 상용화제로 PE-g-MAH(polyethylene-graft-maleic anhydride)를 사용하여 블렌딩하였다. Triphenyl phosphate 함량이 증가할수록 인장강도를 크게 저하시킴을 확인하였다. 하지만 상용화제 첨가로 인하여 기계적 물성이 향상되는 것을 확인하였다. Triphenyl phosphate의 분산성의 향상은 SEM 분석을 통해서 확인하였다. HDPE/EPDM/boron carbide/triphenyl phosphate의 내열성과 난연성을 측정하기 위해서 TGA 분석과 LOI 분석을 진행하였다. 분산성이 향상됨에 따라서 triphenyl phosphate 첨가제의 기본적인 특성인 내열성과 난연성이 향상되었으며, 그 결과로 자기 소화성인 21% 이상의 한계산소지수(LOI)를 가지는 HDPE/EPDM/boron carbide/triphenyl phosphate 블렌드를 얻을 수 있었다.

• KSTLE International Journal
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• 제6권2호
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• pp.39-44
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• 2005

Friction and wear properties of the Boron carbide ($B_{4}C$) coating 100 nm thickness were studied under various relative humidity (RH). The boron carbide film was deposited on silicon substrate by DC magnetron sputtering method using $B_{4}C$ target with a mixture of Ar and methane ($CH_4$) as precursor gas. Friction tests were performed using a reciprocation type friction tester at ambient environment. Steel balls of 3 mm in diameter were used as counter-specimen. The results indicated that relative humidity strongly affected the tribological properties of boron carbide coating. Friction coefficient decreased from 0.42 to 0.09 as the relative humidity increased from $5\%$ to $85\%$. Confocal microscopy was used to observe worn surfaces of the coating and wear scars on steel balls after the tests. It showed that both the coating surface and the ball were significantly worn-out even though boron carbide is much harder than the steel. Moreover, at low humidity ($5\%$) the boron carbide showed poor wear resistance which resulted in the complete removal of coating layer, whereas at the medium and high humidity conditions, it was not. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) analyses were performed to characterize the chemical composition of the worn surfaces. We suggest that tribochemical reactions occurred during sliding in moisture air to form boric acid on the worn surface of the coating. The boric acid and the tribochemcal layer that formed on steel ball resulted in low friction and wear of boron carbide coating.

• 한국세라믹학회지
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• 제33권4호
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• pp.464-470
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• 1996

Toughening mechanism of boron carbide ceramics by the addition of titanium boride was investigated. Speci-men was prepared by hot pressing of boron carbide with upto 30vol% of titanium boride particulates. Toughness of boron carbide ceramics was increased from 4.7 MPa m1/2 to 6.3 MPa m1/2 with 15 vol% TiB2 addition. But further increase of TiB2 content results in slow decrease of toughness. From microstructure evaluation and crack propagation behavior it is concluded that the major toughening mechanism is crack deflection pheno-mena.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.114-115
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• 2018

To develop an effective shielding material for spent fuel that emits fast neutrons is necessary. In this study, thermal neutron and fast neutron shielding performance of polyethylene coated boron carbide-incorporated cement paste was quantitatively analyzed by Monte Carlo N-Particle transport code (MCNP) simulations. As the results of the simulations, fast neutrons were effectively shielded through large quantity of hydrogen and boron elements in polyethylene and boron carbide.

• 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.

• KSTLE International Journal
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• 제4권2호
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• pp.56-59
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• 2003

Boron carbide thin coatings were deposited on silicon wafers by DC magnetron sputtering using a ${B}_4$C target with Ar as processing gas. Various amounts of methane gas (${CH}_4$) were added in the deposition process to better understand their influence on tribological properties of the coatings. Reciprocating wear tests employing an oscillating friction wear tester were performed to investigate the tribological behaviors of the coatings in ambient environment. The chemical characteristics of the coatings and worn surfaces were studied using X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). It revealed that ${CH}_4$addition to Ar processing gas strongly affected the tribologcal properties of sputtered boron carbide coating. The coefficient of friction was reduced approximately from 0.4 to 0.1, and wear resistance was improved considerably by increasing the ratio of ${CH}_4$gas component from 0 to 1.2 vol %. By adding a sufficient amount of ${CH}_4$(1.2 %) in the deposition process, the boron carbide coating exhibited lowest friction and highest wear resistance.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.78-84
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• 2003

Boron carbide thin coatings were deposited on silicon wafers by DC magnetron sputtering using a $B_4C$ target with As as processing gas. Various amounts of methane gas $(CH_4)$ were added in the deposition process to better understand their influence on tribological properties of the coatings. Reciprocating wear tests employing an oscillating friction wear tester were performed to investigate the tribological behaviors of the coatings in ambient environment. The chemical characteristics of the coatings and worn surfaces were studied using X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). It revealed that $CH_4$ addition to As processing gas strongly affected the tribologcal properties of sputtered boron carbide coating. The coefficient of friction was reduced approximately from 0.4 to 0.1, and wear resistance was improved considerably by increasing the ratio of $CH_4$, gas component from 0 to $1.2\;vol\;\%$. By adding a sufficient amount of $CH_4\;(1.2\%)$ in the deposition process, the boron carbide coating exhibited lowest friction and highest wear resistance.

• 한국세라믹학회지
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• 제27권4호
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• pp.553-559
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• 1990

The nonuniform shrinkage has been investigaed in pressureless sintering of $\alpha$-SiC, where born carbide and phenolic resin as a carbon source are used as densification aids. Compacted specimens, prepared from the granulated powder, were sintered at 215$0^{\circ}C$ for 30min in Ar atmosphere. Using the fresh and unseasoned graphite crucible, the upwarped specimens were obtained, while specimens were uniformly shrunk in the seasoned crucible. This effect is mainly due to the nonuniform distributjion of boron carbide during heatig, which originates in the reaction of boron carbide with CO gas, providing from the result of SiO2 reduction with carbon during heating.

• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3121-3125
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• 2023

Neutron conversion detectors that use ¹⁰B-enriched boron carbide are feasible alternatives to ³He-based detectors. We prepared boron carbide films at micron-scale thickness using direct-current magnetron sputtering. The structural characteristics of natural B₄C films, including density, roughness, crystallization, and purity, were analyzed using grazing incidence X-ray reflectivity, X-ray diffraction, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and scanning electron microscopy. A beam profile test was conducted to verify the practicality of the ¹⁰B-enriched B₄C neutron conversion layer. A clear profile indicated the high quality of the neutron conversion of the boron carbide layer.

• 대한기계학회논문집B
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• 제36권7호
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• pp.731-736
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• 2012

열플라즈마 시스템을 이용하여 붕소 함유 나노입자를 제조하기 위한 새로운 방법이 시도되었다. $BCl_3$ 와 $CH_4$ 전구체 기체를 열플라즈마 영역으로 분사하여 고온에서 분해시킨 후, 기체상 응핵 및 성장 과정을 통하여 붕소 또는 붕소 카바이드 입자를 제조하였다. X 선 광분자 분석법을 이용하여 입자 표면의 화학적 결합 상태 및 카바이드와 관련된 B-C 결합 구조 내의 붕소와 탄소의 원자 비율을 측정 및 분석하였다. 또한 나노입자 형상 및 크기 분석을 위해 주사식 투과현미경과 전자에너지손실분광법이 이용되었다. 제조된 나노입자는 30-70 nm 내의 크기 분포를 갖고 있으며, $BCl_3$ 와 $CH_4$ 전구체 기체가 각각 20 sccm, 25 sccm 사용되었을 때 B-C 결합 구조 내의 붕소와 탄소의 비는 2.13 이었다.