• 제목/요약/키워드: surface damage

검색결과 2,303건 처리시간 0.031초

표면피복재 종류에 따른 철근콘크리트의 철근 부식특성에 관한 실험적 연구 (An Experimental Study on the Corrosion Characteristics of Reinforcement Concrete According to Types of Surface Covering Material)

  • 김갑수;장종호;김재환;김용로;오시덕;김무한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2003년도 학술.기술논문발표회
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    • pp.39-43
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    • 2003
  • Chloride ions are considered to be the major cause of steel corrosion in concrete structures exposed to seashore environments and also permeation of chloride is controlled by chloride diffusion. Therefore, the study on chloride diffusion of concrete have been done so far by many researchers. It is reported that coating material as surface covering material is effect about deterioration of salt damage and carbonation, therefore these materials are important in durability of concrete structure. In this study, corrosion characteristics of reinforcement concrete according to types of surface covering material were evaluated by water-cement ratio, chloride penetration by age on the corrosion area rate and mass decrement of reinforcement. And it is considered that the result of this study on application of the corrosion characteristics of reinforcements under salt damage environmental will be suggested as fundamental data of control performance of salt damage. It is performed that comparison and examination of control performance of salt damage by the corrosion characteristics under salt damage environmental.

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CMOS 소자를 위한 NiSi의 surface damage 의존성 (The dependence of NiSi for CMOS Technology on Surface Damage)

  • 지희환;배미숙;이헌진;오순영;윤장근;박성형;왕진석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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    • pp.167-170
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    • 2002
  • The influence of Si surface damage on Ni-silicide with TiN Capping layer and the effect of $H_2$ anneal are characterized. Si surface is intentionally damaged using Ar Sputtering. The sheet resistance of NiSi formed on damaged silicon increased rapidly as Ar sputtering time increased. However, the thermal stability of Ni-Si on the damage silicon was more stable than that on at undamaged Si, which means that damaged region retards the formation of NiSi. It was shown that $H_2$ anneal and TiN capping is highly effective in reducing NiSi sheet resistance.

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화학제염공정에서 환원공정조건에 따른 Inconel 600의 부식손상 특성 (Corrosion Damage Characteristics of Inconel 600 with Reduction Conditions in Chemical Decontamination Process)

  • 한민수;정광후;양예진;박일초;이정형;김성종
    • 한국표면공학회지
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    • 제50권5호
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    • pp.332-338
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    • 2017
  • In this study, we evaluated tendency and degree of corrosion damages of Inconel 600 after chemical decontamination treatments under three different conditions. In the decontamination processes, the oxidation and reduction were performed as one cycle. Each process was continued up to 5 cycles. Characteristics of corrosion under decontamination processes were evaluated by Tafel analysis and weight loss. Characteristics of surface damage were observed by scanning electron microscope(SEM) and three-dimensional(3D) microscope. As the cycle proceeded, weight loss and corrosion current density increased. Intergranular corrosion damage occurred on the surface of the materials. The result revealed that the surface of Inconel 600 was attacked by the strong acid solution under all chemical decontamination processes, but the degree of the corrosion damage was different depending on the processes.

환경열화에 의한 가선재의 피로거동 (Fatigue Behavior of Catenary Wires by Environments Degradation)

  • 김용기;장세기
    • 한국철도학회논문집
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    • 제7권1호
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    • pp.14-19
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    • 2004
  • The effect of surface damage on fatigue properties of catenary wires were investigated to estimate their service lift. As surface defects of the wires caused by surface corrosion increase, surface roughness gets worse, and as roughness increases, it is easy for moisture coming from rain and dew to be condensed around uneven parts of the surface. The condensed moisture causes a locally severe corrosion which leads to damage of the wires. Corrosion of catenaty wires can make their actual lifetime shorter than that originally designed. The amount of decrease was more prominent as environmental conditions became more corrosive. They are also vibrated with some amplitude everytime pantographs touch contact line. The frequent cyclic load on the wire may result in a fatigue fracture. Surface damage by corrosion can make formation of crack initiation at fatigue. In the present study, the fatigue life of the used wire was measured 35 to 50% compared with that of new one in average.

다결정 실리콘 웨이퍼의 표면 텍스쳐링을 위한 습식 화학 식각에 대한 연구 (Investigation of Wet Chemical Etching for Surface Texturing of Multi-crystalline Silicon Wafers)

  • 김범호;이현우;이은주;이수홍
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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    • pp.19-20
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    • 2006
  • Two methods that can reduce reflectance in solar cells are surface texturing and anti-reflection coating. Wet chemical etching is a typical method that surface texturing of multi-crystalline silicon. Wet chemical etching methods are the acid texturization of saw damage on the surface of multi-crystalline silicon or double-step chemical etching after KOH saw damage removal too. These methods of surface texturing are realized by chemical etching in acid solutions HF-$HNO_3$-$H_2O$. In this solutions we can reduce reflectance spectra by simple process etching of multi-crystalline silicon surface. We have obtained reflectance of 27.19% m 400~1100nm from acidic chemical etching after KOH saw damage removal. This result is about 7% less than just saw damage removal substrate. The surface morphology observed by microscope and scanning electron microscopy (SEM).

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나노 버블과 메가소닉 초음파를 이용한 반도체 웨이퍼 세정장치 개발 (Development of Wafer Cleaning Equipment Using Nano Bubble and Megasonic Ultrasound)

  • 김노유;이상훈;윤상;정용래
    • 반도체디스플레이기술학회지
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    • 제22권4호
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    • pp.66-71
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    • 2023
  • This paper describes a hybrid cleaning method of silicon wafer combining nano-bubble and ultrasound to remove sub-micron particles and contaminants with minimal damage to the wafer surface. In the megasonic cleaning process of semiconductor manufacturing, the cavitation induced by ultrasound can oscillate and collapse violently often with re-entrant jet formation leading to surface damage. The smaller size of cavitation bubbles leads to more stable oscillations with more thermal and viscous damping, thus to less erosive surface cleaning. In this study, ultrasonic energy was applied to the wafer surface in the DI water to excite nano-bubbles at resonance to remove contaminant particles from the surface. A patented nano-bubble generator was developed for the generation of nano-bubbles with concentration of 1×109 bubbles/ml and nominal nano-bubble diameter of 150 nm. Ultrasonic nano-bubble technology improved a contaminant removal efficiency more than 97% for artificial nano-sized particles of alumina and Latex with significant reduction in cleaning time without damage to the wafer surface.

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화포에 의해 손상된 날개의 공력특성에 관한 연구 (A Study on the Aerodynamic Characteristic of Gunfire Damaged Airfoil)

  • 이기영;정형석;김시태
    • 한국군사과학기술학회지
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    • 제11권2호
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    • pp.144-151
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    • 2008
  • An experimental study has been conducted to investigate the effects of circular damage hole on the characteristics of airfoil performance. The damage on a wing created from a hit by anti-air artillery was modeled as a circular hole. Force balance measurements and static pressure measurements on the wing surface were carried out for the cases of having damage holes of 10% chord size at quarter chord and/or half chord positions. All experiments were conducted at Reynolds number of $2.85\times10^5$ based on the chord length. The surface pressure data show big pressure alterations near the circular damage holes. This abnormal surface pressure distribution produces shear stress that could lead to the acceleration of the structural degradation of the wing around the circular damage hole. However, in spite of the existence of circular damage holes, the measured force data indicated the only a slight decrease in lift accompanied by increase in drag compared to the results of undamaged one. The influence of damage hole on the aerodynamic performance was increased as the location of damage moved to the leading edge. The effect on the control force was insignificant when the damaged size was not large.

집속 이온빔을 이용한 투과 전자 현미경 시편의 표면 영향에 관한 연구 (Study on Surface Damage of Specimen for Transmission Electron Microscopy(TEM) Using Focused Ion Beam(FIB))

  • 김동식
    • 전자공학회논문지 IE
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    • 제47권2호
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    • pp.8-12
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    • 2010
  • TEM(Transmission Electrion microsopy) 투과전자현미경은 재료의 기초 구조 분석과 반도체 또는 생물시편의 미세 구조분석에 널리 사용되는 장비이다. TEM 분석은 필수적으로 목적에 부합되는 적절한 시편제작이 수반되어야 한다. 다양한 전자 현미경 시편 제작 방법 중 본 논문에서는 FIB(Focus Ion Beam)를 이용한 시편 제작법 중 시편에 입사되는 에너지와 이온 Gun과 시편과의 상호 각도, 이온 밀링 깊이 조절 등의 실험을 통하여 표면 손상 최소화를 벌크 웨이퍼와 패턴화된 시편에서 실험하였다. 최소화된 표면 영향성(약 5nm)을 패턴화된 시편에 구현하였다.

Surface Damage Accumulation in Alumina under the Repeated Normal-Tangential Contact Forces

  • Lee, Kwon-Yong;Choi, Sung-Jong;Youn, Ja-Woong
    • KSTLE International Journal
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    • 제1권1호
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    • pp.48-51
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    • 2000
  • Surface damage accumulation of alumina ceramics under the cyclic stress state was analyzed. The alternating stress state in repeat pass sliding contact was simulated by a synchronized biaxial (normal and tangential) repeated indentation technique. Wear debris formation mechanism through damage accumulation and fatigue grain failure in both alumina ceramic balls and flat disks was confirmed, and the contact induced surface degradation due to fatigue cracking accumulation was quantified by measuring vertical contact displacement. Variation of structural compliance (slope of load-displacement curve) of two contacting bodies was expressed as a variation of the apparent elastic property, called pseudo-elastic constant, of the contact system.

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도로 노면 조건을 고려한 차량 엔진 주변 부품의 피로손상도 분석 (Analysis of Fatigue Damage of the parts around the vehicle engine with Respect to Road surface conditions)

  • 신성영;김찬중;이봉현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2014년도 추계학술대회 논문집
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    • pp.581-586
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    • 2014
  • In general vibration test considers both harmonic vibration and random vibration, When developing the vehicle component. But the effect of harmonic vibration is larger in the parts around the vehicle engine, sole testing the harmonic vibration is considered. In this study, the fatigue damage of the linear system fixed around the engine is analyzed when the effect of random vibration is higher, harsher than the normal road surface condition. In condition the vehicle speed and the engine RPM are similar, the higher the harshness of the road surface condition is, the larger the fatigue damage level is. Therefore both random vibration and harmonic vibration must be considered in vibration test of components around the engine. Proposing the sine on random(SOR) vibration test that can exam considering both of vibrations, harmonic and random.

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