• Title/Summary/Keyword: Post-heat-treatment

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Improvement of carrier mobility on Silicon-Germanium on Insulator MOSFEI devices with a Si-strained layer (Si-strained layer를 가지는 Silicon-Germanium on Insulator MOSFET에서의 이동도 개선 효과)

  • Cho, Won-Ju;Koo, Hyun-Mo;Lee, Woo-Hyun;Koo, Sang-Mo;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.7-8
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    • 2006
  • The effects of heat treatment on the electrical properties of SGOI were examined. We proposed the optimized heat treatments for improving the interfacial electrical properties in SGOI-MOSFET. By applying the additional pre-RTA(rapid thermal annealing) before gate oxidation and post-RTA after dopant activation, the driving current, the transconductance, and the leakage current were improved significantly.

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Evaluation of Mechanical Properties of Welded Joints by an Instrumented Indentation Test and Fatigue Life Evaluation (계장화 압입시험에 의한 용접부의 물성 측정 및 피로수명 예측)

  • Goo, Byeong-Choon;Lee, Dong-Hyung;Kwon, Dong-Il;Choi, Yeol
    • Journal of the Korean Society for Railway
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    • v.7 no.2
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    • pp.142-148
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    • 2004
  • When material properties depend much on positions in a material or it is difficult to make test specimens from a material or component, an instrumented indentation test described in ISO 14577-1, 14577-2 or KS B 0950 can be used to measure material properties and damage. In this study, first of all, the principals of the instrumented indentation test, KS B 0950 are introduced and yield strengths, tensile strengths and work hardening exponents of base materials, heat affected zones and weld materials are measured. In addition, the influence of post-weld heat treatment on the material properties is investigated. Finally the fatigue lift of butt welded specimens are evaluated by the local strain approach. To calculate local strains and stresses, elasto-plastic finite element analysis is conducted using the measured properties.

Evaluation of mechanical properties of welding materials by an instrumented indentation test (계장화 압입시험에 의한 용접부의 물성 평가)

  • Koo, Byung-Chun;Kwon, Dong-Il;Choi, Yeol
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.117-119
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    • 2003
  • When material properties depend much on positions in a material or it is difficult to make test specimens from a material or component, an instrumented indentation test described in ISO 14577-1, 14577-2 or KS B 0950 can be used to measure material properties and damage. In this study, first of all, the principals of the instrumented indentation test, KS B 0950 are introduced and yield strengths, tensile strengths and work hardening exponents of base materials, heat affected zones and weld materials are measured. In addition, the influence of post-weld heat treatment on the material properties are investigated.

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Control of ITO/PET Thin Films Depending on the Ratio of Oxygen Partial Pressure in Sputter (스퍼터의 산소분압비율에 의존한 ITO/PET박막의 조절)

  • 김현후;신재혁;신성호;박광자
    • Journal of the Korean institute of surface engineering
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    • v.32 no.6
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    • pp.671-676
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    • 1999
  • ITO (indium tin oxide) thin films on PET (polyethylene terephthalate) substrate have been deposited by a dc reactive magnetron sputtering without heat treatments such as substrate heater and post heat treatment. Each sputtering parameter during the sputtering deposition is an important factor for the high quality of ITO thin films deposited on polymeric substrate. Particularly, the material, electrical and optical properties of as-deposited ITO oxide films are dominated by the ratio of oxygen partial pressure. As the experimental results, the excellent ITO films are prepared on PET substrate at the operating conditions as follows : operating pressure of 5 mTorr, target-substrate distance of 45mm, do power of 20~30W, and oxygen gas ratio of 10%. The optical transmittance is above 80% at 550 nm, and the sheet resistance and resistivity of films are 24 Ω/square and $1.5\times$10$^{-3}$ Ωcm, respectively.

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Effects of PWHT on the toughness of weld HAZ in Cu-bearing HSLA-100 steel (Cu를 함유한 HSLA-100강 용접 열 영향부의 인성에 미치는 PWHT의 영향)

  • 박태원;심인옥;김영우;강정윤
    • Proceedings of the KWS Conference
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    • 1995.04a
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    • pp.91-93
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    • 1995
  • A study was made to examine the effects of post-weld heat treatment (PWHT) on the toughness and microstructures in the weld heat-affacted zone(HAZ) of Cu-bearing HSLA-100 steel. The Gleeble thermal/mechanical simulator was used to simulate the weld HAZ. The behavior of Cu-precipitates in HAZ is similar to that in base plate. PWHT at 55$0^{\circ}C$ shows highest hardness and lowest toughness, whereas PWHT at $650^{\circ}C$ shows reasonable toughness. Cu precipitated during agcing for increasing the strength of base metal is dissolved during single thermal cycle to 135$0^{\circ}C$ and is precipitated little on cooling and heating during subsequent weld thermal cycle. It precipitates by introducing PWHT.

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Effects of Heat Treatment on the Radiosensitivity of Salmonellae (Salmonellae 균(菌)의 방사선 감수성(感受性)에 미치는 열처리(熱處理)의 영향)

  • Choi, Eon-Ho;Yang, Jae-Seung;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.10 no.1
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    • pp.88-91
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    • 1978
  • When the food poisoning bacteria Salmonella enteritidis and S. typhimurium were treated with radiation (cobalt-60 r-rays) and heat (10 minutes at $45^{\circ}C\;or\;50^{\circ}C$), their sterilizing effect was revealed differently depending on the order of treatments. Post-irradiation heating showed a synergistic effect whereas pre-irradiation heating revealed the opposite effect and the effects differed slightly with heating temperature.

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Characteristics of ITO Films Deposited by dc Magnetron Sputter Using Powder Target (분말타겟의 dc 마그네트론 스퍼터에 의한 ITO박막의 특성)

  • 김현후;신성호;신재혁;박광자
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.427-431
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    • 2000
  • ITO (indium tin oxide) thin films on PET (polyethylene terephthalate) and glass substrates have been deposited by a dc magnetron sputtering without heat treatments such as substrate heater and post heat treatment. Each sputtering parameter during the sputtering deposition is an important factor for the high quality of ITO thin films deposited on polymeric substrate. Particularly, the material, electrical and optical properties of as-deposited ITO oxide films are dominated by sputtering power, oxygen partial pressure and films thickness. As the experimental results, the XRD patters of ITO films are influenced by sputtering power and pressure. As the power and pressure are increased, (411) peak is grown suddenly. the electrical resistivity is also increased, as the sputteing power and pressure are increased. Transmittance of ITO thin films in visible light ranges is lowered with increasing the sputtering power and film thickness. Reflectance of ITO films in infia-red region is decreased, as the power and pressure is increased.

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Study on Softening Characteristics of 9Cr-1Mo Steel Weldments for High Temperature and Pressure Vessels Application (고온고압장치 적용을 위한 9Cr-1Mo강 용접부의 연화특성에 관한 연구)

  • 이영호;이규천;윤의박;김기철
    • Journal of Welding and Joining
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    • v.10 no.3
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    • pp.40-53
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    • 1992
  • 고온고압장치(High Temperature and Pressure Vessels)의 적용을 위한 기초연구로서 9Cr-1Mo강 용접부의 연화특성에 대하여 검토하였다. 9Cr-1Mo 강재에 Bead-on-Plate용접을 실시한 후, 용접부의 기계적 성질과 그 현미경조직관찰 및 미세경도를 측정한 결과, As-Welded 및 용접 후열처리(PWHT)등의 조건에 관계없이 용접열향부의 변태역과 템퍼링역의 경계에서 모재의 경 도보다 낮은 경도값(연화역)을 나타내었으며 이러한 원인은 결정립계(Grain boundary)에 석출 되는 탄화물의 형성에 의한 뜨임 현상임이 판명되었다.

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ITO Films Deposited by Sputter Method of Powder Target at Room Temperature. (상온에서 분말타겟의 스퍼터에 의해 증착된 ITO박막)

  • 김현후;이재형;신성호;신재혁;박광자
    • Journal of the Korean institute of surface engineering
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    • v.33 no.5
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    • pp.349-355
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    • 2000
  • Indium tin oxide (ITO) thin films have been deposited on PET (polyethylene terephthalate) and glass substrates by a do magnetron sputter method of powder target without heat treatments such as substrate heater and post heat treatment. During the sputtering deposition, sputtering parameters such as sputtering power, working pressure, oxygen gas mixture, film thickness and substrate-target distance are important factors for the high quality of ITO thin films. The structural, electrical and optical properties of as-deposited ITO oxide films are investigated by sputtering power, oxygen partial pressure and films thickness among the several sputtering conditions. XRD patterns of ITO films are affected by sputtering power and pressure. As the power and pressure are increased, (411) and (422) peaks of ITO films are grown strongly. Electrical resistivity is also increased, as the sputtering power and pressure are increased. Transmittance of ITO thin films in the visible light ranges is lowered with an increase of sputtering power and film thickness. Reflectance of ITO films in infra-red region is decreased, as the power and pressure is increased.

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원자로압력용기강 용접열영향부(HAZ)의 샤피시험편 노치 위치설정에 대하여

  • 김주학;변택상;지세환;국일현;홍준화
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.11b
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    • pp.557-562
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    • 1996
  • 조사전 및 감시시험시 용접열영향부(heat affected zone, HAZ)의 인성평가를 위해 제작되는 샤피(Charpy) 충격시험편의 노치(notch) 위치에 대하여 현재의 규정에 대한 타당성을 검토하였다. 적용규정은 HAZ 시험편의 노치위치를 용접용융선(fusion line, FL) + 모재측 0.8 mm 로 제한하고 있다. 그러나, 본 연구결과, 이 부위는 다층(multipass) 용접시 후속열이력에 의해 결정립이 미세화되어, 인장강도와 경도 및 충격인성이 모재나 용접부에 비하여 양호하게 나타났다. 한편, FL + 4 mm 이상의 다른 위치에서는 강도와 경도 및 충격인성이 모두 모재와 용접부에 비하여 낮은 값을 보였다. 이는 다층용접에 의한 후속열이력 및 용접후열처리(post weld heat treatment, PWHT)에 의해 금속조직학적 영향을 받은 것으로 판단되었다. 일련의 시험결과로부터, 조 사전 및 감시시험용 샤피충격시험편의 HAZ 에 있어서의 노치위치에 대한 현재의 규정을 재검토할 필요가 있음을 제안하였다.

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