• Title/Summary/Keyword: boron effect

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Co-sintering of M2/316L Layers for Fabrication of Graded Composite Structures

  • Firouzdor, V.;Simchi, A.;Kokabi, A.H.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.696-697
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    • 2006
  • This paper presents the densification and microstructure evolution of bilayer components made from 316L stainless steel and M2 High speed steel during co-sintering process. The sintering was carried out at temperatures ranging from $1230-1320^{\circ}C$ in a reducing atmosphere. The addition of boron to 316L was examined in order to increase the densification rate and improve the sintering compatibility between the two layers. It was shown that the mismatch strain bettwen the two layers induces biaxial stresses during sintering, influencing the densification rate. The effect of boron addition was also found to be positive as it improves the bonding between the two layers.

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Weldability of boron containing low carbon quenched and tempered 60kg/mm$^{2}$ steel with low cold cracking susceptibility (저탄소 B 첨가 60kg/mm$^{2}$급 저균열감수성 조질고강력강의 용접성)

  • 장웅성;김태웅;장래웅;엄기원
    • Journal of Welding and Joining
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    • v.7 no.1
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    • pp.59-66
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    • 1989
  • The weldability and joint performance were evaluated for newly developed 60kg/mm$\^$2/ steel which had low cold cracking susceptibility. The main results obtained were as follows; In case of quenched and tempered 60kg/mm$\^$2/ steels, it was very effective to improve weldability and joint performance by lowering carbon and Pcm level. Very small addition of about 0.001 to 0.002wt% boron exhibited an appreciable compensation effect on strength which was decreased by lowering carbon and Pcm level. As a result, the newly developed steel was able to be welded without preheating and exhibited superior joint performance to conventional steels.

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Effect of residual oxygen in a vacuum chamber on the deposition of cubic boron nitride thin film

  • Oh, Seung-Keun;Kang, Sang Do;Kim, Youngman;Park, Soon Sub
    • Journal of Ceramic Processing Research
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    • v.17 no.7
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    • pp.763-767
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    • 2016
  • The structural characterization of cubic boron nitride (c-BN) thin films was performed using a B4C target in a radio-frequency magnetron sputtering system. The deposition processing conditions, including the substrate bias voltage, substrate temperature, and base pressure were varied. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to analyze the crystal structures and chemical binding energy of the films. For the BN film deposited at room temperature, c-BN was formed in the substrate bias voltage range of -400 V to -600 V. Less c-BN fraction was observed as the deposition temperature increased, and more c-BN fraction was observed as the base pressure increased.

Effects of Boron Application on the Forage Traits in the Pure and Mixed Swards of Orchardgrass and White Clover. II. Changes in the yields and concurrence index of forages (Orchardgrass 및 White clover의 단 파 및 혼파 재배에서 붕소의 시용이 목초의 여러 특성에 미치는 영향. II. 초종별 건물수량 및 식생 경합지수의 변화)

  • Jung, Yeun-Kyu
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.23 no.3
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    • pp.159-168
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    • 2003
  • This pot experiment was conducted in order to find out the effects of boron application($B_{0}$ /; control, $B_1$; 0.2, $B_2$; 2.0,$ B_3$; 6.0, $B_4$; 15.0 B me/pot) on the forage performance of pure and mixed cultures of orchardgrass and white clover. The 2nd part was concerned with the changes in the forage yields and concurrence index. The results obtained are summarized as follows: 1. The optimum boron application($B_2$) generally resulted in the increase of both forage yields, but the effects of boron application on them were different according to the forage species, whether it was a pure or mixed cultures, additional fertilization, and cutting order. The effects of boron application on the forage productivity were more obvious in white clover than in orchardgrass. 2. Owing to the decline of white clover as affected by the application of additional fertilizers, especially N, in the grass-clover mixed cultures, the effects of boron application on the white clover yields showed a numerical inferiority compared with the pure culture. It was recognized that the yield increase and botanical composition of white clover in grass-clover mixed cultures could be regulated by the application of additional fertilizers and boron. 3. The toxic boron application($B_3$ and $B_4$) resulted in a decreased yield of both forages. The yield change of orchardgrass tended to be similar between pure and mixed cultures, whereas it of white clover tended to be more negative in mixed than in pure cultures. 4. With the application of additional fertilizers, especially N, the botanical composition and concurrence index in grass-clover mixed cultures were relatively increased in orchardgrass, and decreased in white clover. The botanical composition of orchardgrass increased from 55% to 75%, whereas it of white clover decreased from 45% in the first half cutting to 25% in the second half cutting, respectively.

Optimization on the fabrication process of Si pressure sensors utilizing piezoresistive effect (압저항 효과를 이용한 실리콘 압력센서 제작공정의 최적화)

  • Yun Eui-Jung;Kim Jwayeon;Lee Seok-Tae
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.1
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    • pp.19-24
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    • 2005
  • In this paper, the fabrication process of Si pressure sensors utilizing piezoresistive effect was optimized. The efficiency(yield) of the fabrication process for Si piezoresistive pressure sensors was improved by conducting Si anisotrophic etching process after processes of piezoresistors and AI circuit patterns. The position and process parameters for piezoresistors were determined by ANSYS and SUPREM simulators, respectively. The measured thickness of p-type Si piezoresistors from the boron depth-profile measurement was in good agreement with the simulated one from SUPREM simulation. The Si anisotrohic etching process for diaphragm was optimized by adding ammonium persulfate(AP) to tetramethyl ammonium hydroxide (TMAH) solution.

Effect Boron and Silicon on Various Properties of Dental Cobalt-Chromium Alloys (치과용 Co-Cr 합금의 제성질에 미치는 Boron과 Silicon의 영향)

  • Jung, Jong-Hyun
    • Journal of Technologic Dentistry
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    • v.14 no.1
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    • pp.119-132
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    • 1992
  • This paper aims to investigate the effect of B and Si upon the mechanical properties, microstructure and corrosion resistance of Co-Cr base alloy. Ten groups of alloy ingot ingot with various contents of B and Si were remelted by high frequency electrical induction furnace and cast into tensile specimen of ADA Specification No. 14 Tensile and hardness test were carried out by Amsler and Rockwell hardness tester(R-30N), respectively. The microstructures of specimen were observed by SEM. The results obtained are summarized as follows : 1. As B content is increased, tensile strength, yield strength and Rockwell hardness number(R-30N) are also increased significantly, while the elongation is decreased significantly. 2. As Si contect os increased, no significant chang in tensile strength is noticed, yield strength is slightly decreased, but Rockwell hardness number(R-30N) is moderately in creased, Elongation marks maxium value with 1% Si content while with more than 1% Si it is decreased. 3. As B content is increased corrosion resistance is decreased and is at best with 1.5% B content. Corrosion resistance is increased with the increase of Si content and the alloys with Si over 3.0% showed corrosion resistance. 4. As B content increased, precipitates are increased in number at grain boundaries. The grain size tends to become coarse with the increase of Si content. 5. Co rich-Cr alloy is present through matrix whereas at the grain boundaries Cr base precipitates are primarily formed.

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