• 제목/요약/키워드: Cold-hot impact test

검색결과 7건 처리시간 0.022초

자동차 터치스크린용 실버페이스트 종류에 따른 신뢰성 테스트 특성 연구 (A Studies on the Characteristics of Reliability Test by Automotive Touch Screen Silver Pastes)

  • 김중원;최웅세
    • 전기전자학회논문지
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    • 제20권2호
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    • pp.205-208
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    • 2016
  • 본 논문에서는 서로 다른 터치스크린용 실버페이스트를 본딩 방식으로 ITO 필름(ITO : Indium Tin Oxide film)위에 전도성 패턴을 형성하고 5장씩 본딩하여 건조 하였다. 여기서 건조 조건은 ITO 필름( ITO film)이 산화가 발생하지 않는 조건 이다. 신뢰성 테스트는 열 충격테스트와 고온 고습테스트를 진행한다. 각 테스트는 5장씩의 전도성 패턴 본딩상태를 확인한다. 전도성 패턴본딩을 각 240, 480, 615 시간 마다 상태를 확인하였다. 이러한 신뢰성 테스트 통해 서로 다른 실버페이스트의 접착력, 전도성의 변화 등을 알 수 있으므로 품질 저하를 막을 수 있다. 그리고 저온경화 실버페이스트는 표면에 변색이 빨리 올 수 있음을 알 수 있었다.

HY계 고강도 고인성강의 용접성 (Weldability of HY type High Strength-Toughness Steel)

  • 이종봉;안상곤;심인옥
    • Journal of Welding and Joining
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    • 제13권3호
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    • pp.65-76
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    • 1995
  • Weldability of DS100 and HY type high strength-toughness steel plates, tentatively produced as domestic production, was investigated. DS100 and DS130A had nearly same hardenability in HAZ in spite of its difference in Ceq. Based upon the y-groove test results, cold cracking susceptibility of DS130 was superior to that of DS100 because of its lower hydrogen level in weld metal. Solidification cracking tested by the Trans-Varestraint test was occured in all of the weld metals, and its susceptibility was high in the row of DS100, DS130A and DS130B. However, no liquation cracking and ductility-dip cracking tested by the Longi-Varestraint test with 6.0% augmented strain were detected in base metal and reheated weld metal. Toughness in the GMA welding joint was satisfied with the relative Mill Spec, even though welded joint of DS100 had relatively low impact energy especially at the weld metal.

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용융염 침적법에 의한 VC Coating 금형강의 인성에 관한 연구 (A Study on the Toughness of Die Steel Coated with VC (vanadium carbide) by Immersing in Molten Borax Bath)

  • 이병권;남태운
    • 열처리공학회지
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    • 제6권2호
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    • pp.59-69
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    • 1993
  • Bending fracture strength test and impact strength test were made for VC coated die steels treated by immersing in molten borax bath and for hardened steels which were quenched and tempered, in order to clarify the effect of VC coating at $1000^{\circ}C$. The material used in this investigation was representative cold and hot work die steels STD11, STD61. The results obtained are as follows. 1) The bending fracture strength of VC coated die steel (STD11, STD61) was lessened with increasing the thickness of the VC coated layer. 2) With increasing the immersing time (imcreasing the thickness of the VC coated layer) the maximum hardness was obtained at 480 minutes holding, after that holding time hardness was decreased. 3) The impact strength of the VC coated die steel was not decreased. In the casse of STD11, it was higher than that of the quenched condition especially at low tempering temperature, and vice versa at high tempering temperature. However in the case of STD61 shows the result to the contrary.

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휘발유 자동차의 메탄(CH4) 배출특성에 관한 연구 (A Study on Characteristics of Methane Emissions from Gasoline Passenger Cars)

  • 전민선;류정호;유영숙;김종춘;임철수;김대욱;정성운;조석연
    • 한국대기환경학회지
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    • 제21권6호
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    • pp.649-655
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    • 2005
  • Automotive exhaust is suspected to be one of the main reasons of the rapid increase in greenhouse effect gases in ambient air. Although methane emissions are generally orders of magnitude lower than emissions of $CO_{2}$, the global warming potential (GWP) of methane is greater than that of $CO_{2}$. The environmental impact of methane emissions from vehicles is negligible and is likely to remain so for the foreseeable future. In this study, in order to investigate greenhouse gas emission characteristics from gasoline passenger cars, 20 vehicles were tested on the chassis dynamometer and methane emissions were measured. The emission characteristics by model year, mileage, vehicle speed were discussed. Test mode is CVS-15 mode that have been used to regulate for light-duty vehicle in Korea. It was found that $CH_{4}$ emissions showed higher for cold start, old model year and long mileage than hot start, new model year and short mileage, respectively. These results were compared with IPCC emission factors and the overall our results were anticipated to contribute for domestic greenhouse gas emissions calculation.

모바일 기기 사용자는 왜 정보보호에 위험한 행동을 하는가? : 위험행동 결정요인 모델을 중심으로 (Why Do Mobile Device Users Take a Risky Behavior?: Focusing on Model of the Determinants of Risk Behavior)

  • 김종기;김지윤
    • 한국정보시스템학회지:정보시스템연구
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    • 제28권2호
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    • pp.129-152
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    • 2019
  • Purpose The purpose of this study is to empirically identify the risky behavior of mobile device users using the Internet of Things on a situational perspective. Design/methodology/approach This study made a design of the research model based on model of the determinants of risk behavior. Data were collected through a survey including hypothetical scenario. SmartPLS 2.0 was used for the structural model analysis and t-test was conducted to compare the between normal and situational behavior. Findings The results were as follows. First, the central roles of risk propriety and risk perception were verified empirically. Second, we identified the role of locus of control as a new factor of impact on risky behavior. Third, mobile risk propensity has been shown to increase risk perception. Fouth, it has been shown that risk perception does not directly affect risky behavior and reduce the relationship between mobile risk propensity and risk behavior. According to the empirical analysis result, Determinants of risk behavior for mobile users were identified based on a theoretical framework. And it raised the need to pay attention to the impact of locus of control on risk behavior in the IS security field. It provided direction to the approach to risky behavior of mobile device users. In addition, this study confirmed that there was a possibility of taking risky behavior in the actual decision-making.

매트릭스(matrix)형 냉간금형강의 기계적 특성에 미치는 NbC 탄화물 첨가의 영향 (Effect of NbC Carbide Addition on Mechanical Properties of Matrix-Type Cold-Work Tool Steel)

  • 강전연;김호영;손동민;이재진;윤효윤;이태호;박성준;박순근
    • 열처리공학회지
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    • 제28권5호
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    • pp.239-249
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    • 2015
  • Various amount of NbC carbide was intentionally formed in a matrix-type cold-work tool steel by controlled amount of Nb and C addition. And the effect of NbC addition on the mechanical properties was investigated. Four alloys with different Nb and C contents were cast by vacuum induction melting, then hot forging and spheroidizing annealing were conducted. The machinability of the annealed specimens was examined with 3 different cutting tools. And tensile tests at room temperature were conducted. After quenching and tempering, hardness and impact toughness were measured, while wear resistance was evaluated by disk-on-plate type wear test. The increasing amount of NbC addition resulted in degraded machinability with increased strength, whereas the absence of NbC also led to poor machinability due to high toughness. After quenching and tempering, the additional NbC improved wear resistance with increasing hardness, whereas it deteriorated impact toughness. Therefore, it could be found that a moderate addition of NbC was desirable for the balanced combination of mechanical properties.

리기다소나무 단판적층재(單板積層材)의 제조조건(製造條件)에 따른 물리적성질(物理的性質) 및 도장성능(塗裝性能) (Suitable Conditions of Producing the LVL from Pitch Pine and its Paint Film Durability)

  • 박상범;공영토;조재명
    • Journal of the Korean Wood Science and Technology
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    • 제17권1호
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    • pp.3-11
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    • 1989
  • 리기다소나무 단판적층재(單板積層材)(LVL)의 가구용재(家具用材)로서의 적합성(適合成) 여부(與否)를 판단(判斷)하기 위한 기초자료(基礎資料)를 제공(提供)하고자 요소 멜라민수지(樹脂)와 페놀수지접착제(樹脂接着劑)를 사용(使用)하여 단판적층재(單板積層材)를 제조(製造), 그 물리적(物理的), 기계적(機械的) 성질(性質), 접착내구성(接着耐久性) 및 제조성능(製造性能)을 검토(檢討)한 결과(結果)는 다음과 같다. 1. 리기다소나무 LVL 제조(製造)를 위한 적정압체시간(適正壓締時間)은 단판(單板)두께 1mm당(當) 45초(秒) 이상이 요구(要求)되었다. 2. 휨강도(强度)는 소재(素材)에 비(比)해 낮았으나 압축강도(壓縮强度)는 비슷하였고 단판(單板)의 두께가 얇을수록 강도(强度)는 증가(增加)하는 경향(傾向)이였다. 3. 충격(衝擊)휨흡수(吸收)에너지는 두께 2.5cm의 경우(境遇) 섬유직각방향(纖維直角方向)(상(上))이 $0.03kg{\cdot}m/cm^2$, 섬유방향(纖維方向)이 $0.24kg{\cdot}m/cm^2$으로 $0.68kg{\cdot}m/cm^2$인 소재(素材)에 비(比)해 매우 낮았다. 4. 열압체시간(熱壓締時間)을 45초(秒)/mm 이상(以上)으로 하면 침지박리(浸漬剝離) 및 한열반복시험시(寒熱反復試驗時), 접착층(接着層)의 박리(剝離), 표면할열(表面割裂), 부풀음, 변색(變色) 등(等)이 발생(發生)하지 않았다. 5. 진공침수시험(眞空侵水試驗)은 결과(結果), 섬유방향(纖維方向)으로서 수축율(收縮率)은 약(約) 1.0%, 섬유직각방향(纖維直角方向)(횡방향(橫方向))은 약(約) 3%였으며, 1~4개(個) 정도(程度)의 표면할제(表面割裂)이 관찰(觀察)되었다. 6. 온냉건고시험(溫冷乾燥試驗)에 의한 리기다소나무 LVL의 도막할열(塗膜割裂)은 전혀 관찰(觀察)되지 않았다. 7. 리기다소나무 LVL을 내장용(內粧用)으로 사용(使用)할 경우(境遇), 부착용화장단판(付着用化粧單板)으로서는 단판자체(單板自體)의 할열(割裂)이 적은 단판(單板)을 사용(使用)하여야 하며 부착용화장단판(付着用化粧單板)과 LVL의 표면(表面)이 서로 직교(直交)되도록 접착(接着)해야 표면할열(表面割裂)의 발생(發生)이 적고 표면부착성(表面付着性)이 향상(向上)되었다. 결론적(結論的)으로 리기다소나무 LVL은 접착성(接着性)은 매우 양호(良好)하였으며 휨강도(强度), 압축강도(壓縮强度) 및 충격(衝擊)휨흡수(吸收)에너지 등(等)은 가구재료(家具材料)로써 적정수준(適正水準)이었으나 단판자체(單板自體)의 옹이 및 할열(割裂)로 인(因)해 가구재료(家具材料)로 사용(使用)할 경우(境遇), 품질(品質)이 좋은 단판(單板) 즉, 화장단판(化粧單板) 등(等)으로 표면(表面)해양 할 것으로 생각되었다.

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