• Tribology and Lubricants
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• 제27권3호
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• pp.147-155
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• 2011

The ceramic coatings are excellent materials of cutting tools and sliding parts. To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process microscopically. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail using in-situ system. In this study, using the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. As results, four modes were observed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. The observation of the microscopic wear by in-situ system can clarify the allowable stress of TiN coating.

• Applied Microscopy
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• 제43권2호
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• pp.88-97
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• 2013

Technical investigation to figure out the problems arising during in-situ heating electron backscatter diffraction (EBSD) analysis inside scanning electron microscopy (SEM) was carried out. EBSD patterns were successfully acquired up to $830^{\circ}C$ without degradation of EBSD pattern quality in steels. Several technical problems such as image drift and surface microstructure pinning were taking place during in-situ experiments. Image drift problem was successfully prevented in constant current supplying mode. It was revealed that the surface pinning problem was resulted from the $TiO_2$ oxide particle formation during heating inside SEM chamber. Surface pinning phenomenon was fairly reduced by additional platinum and carbon multi-layer coating before in-situ heating experiment, furthermore was perfectly prevented by improvement of vacuum level of SEM chamber via leakage control. Plane view in-situ observation provides better understanding on the overall feature of recrystallization phenomena and cross sectional in-situ observation provides clearer understanding on the recrystallization mechanism.

• Corrosion Science and Technology
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• 제23권2호
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• pp.113-120
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• 2024

An attempt was made to apply digital image correlation (DIC) strain analysis to in-situ scanning electron microscopy (SEM) observations of bending deformation to quantify local strain distribution inside a ZnMgAl-alloy coating in deformation. Interstitial-free steel sheets were hot-dipped in a Zn-3Mg-6Al (mass%) alloy melt at 400 ℃ for 2 s. The specimens were deformed using a miniature-sized 4-point bending test machine inside the SEM chamber. The observed in situ SEM images were used for DIC strain analysis. The hot-dip ZnMgAl-alloy coating exhibited a solidification microstructure composed of a three-phase eutectic of fine Al (fcc), Zn (hcp), and Zn2Mg phases surrounding the primary solidified Al phases. The relatively coarsened Zn₂Mg phases were locally observed inside the ZnMgAl-alloy coating. The DIC strain analysis revealed that the strain was localized in the primary solidified Al phases and fine eutectic microstructure around the Zn₂Mg phase. The results indicated high deformability of the multi-phase microstructure of the ZnMgAl-alloy coating.

• 한국기계가공학회지
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• 제10권3호
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• pp.100-107
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• 2011

To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process in great detail. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail, using in-situ system. In this study, based on the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. Consequently, four modes were revealed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. Sc(Severity of contact) can clarify transition condition of those microscopic wear modes.

• 공업화학
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• 제10권1호
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• pp.148-153
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• 1999

2-bromoterephthaloyl chloride와 1,4-bis(p-hydroxybenzoyloxy)butane을 PMMA 용액내에서 중축합시켜 in situ 복합재료를 제조하였다. 이들의 합성확인 및 열적, 기계적 성질은 FT-IR, FT-NMR, DSC와 DMTA에 의해서, 몰폴로지는 광학현미경과 SEM을 사용하여 조사하였다. 합성된 TLCP는 네마틱상을 보였고, 복합재료내 PMMA의 유리전이온도와 기계적 성질은 TLCP의 농도증가와 함께 증가하였다. TLCP domain은 PMMA 매트릭스내에서 미세 분산되었음을 확인하였고 in situ 중합에 의해 제조된 20 wt % TLCP/PMMA 복합재료는 같은 조성의 용액 블렌딩에 의해서 제조된 재료보다 더 높은 기계적 강도와 미세 분산도를 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.70.2-70.2
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• 2015

현재 반도체 및 디스플레이이 공정 분야는 1 um 이상의 입자에서부터 10 nm이하 크기의 오염입자를 제어해야 한다. 현재 오염원인을 파악하기 위해서 사용하는 방법은 공정 완료 후 대상물(웨이퍼 및 글래스)을 CD-SEM (Critical Dimension Scanning Electron Microscope)와 같은 첨단 분석장비를 사용하여 사후 (Ex-situ) 진행하고 있다. 이러한 방법은 오염원이 이미 공정 대상물을 오염시키고 난 후 그 원인을 분석하는 방법으로 그 원인을 찾기가 어려울 뿐만 아니라, 최근 공정관리가 공정 진행 중(In-situ) 행해져야 하는 추세로 봤을 때 합당한 방법이라 할 수 없다. 이를 해결하기 위해 진공공정 중 레이저를 이용하여 측정하고자 하는 여러 시도들이 있었지만, 여전히 긍정적인 답변을 보여주지 못하고 있다. 본 발표에서 소개하는 PCDS (Particle Characteristic Diagonosis System)은 PBMS (Particle Beam Mass Spectrometer)와 SEM (Scanning Electron Microscope), 그리고 EDS (Energy Dispersive X-ray Spectroscopy)를 통합하여 만든 시스템으로 진공공정 중 (In-situ) 챔버 내부에서 발생하고 있는 입자의 크기 분포, 입자의 형상, 그리고 입자의 성분을 실시간으로 분석할 수 있는 방법을 제공한다. 이러한 방법 (PCDS)에 대한 개념과 원리, 그리고 현재까지 개발된 단계에서 얻어진 결과에 대해 소개할 것이다.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 1993년도 제24회 학술대회 연제 초록
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• pp.22-22
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• 1993

• 대한금속재료학회지
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• 제48권7호
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• pp.683-689
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• 2010

In this study, FeAl based intermetallic matrix composites reinforced with in-situ synthesized TiC particles were fabricated by an in-situ liquid mixing process. The microstructures, mechanical properties and fracture behaviors of the in-situ liquid mixing processed composite were investigated and compared with the vacuum suction casting processed composite. The results showed that the in-situ formed TiC particles exhibited fine and uniform dispersion in the liquid mixing processed composite, while significant grain boundary clustering and coarsening of TiC particles were obtained by the vacuum suction process. It was also shown in both types of composites that the hardness and bending strength were increased with the increase of the TiC volume fractions. Through the study of fractography in the bending test, it was considered that the TiC particles prohibited brittle intergranular fracture of FeAl intermetallic matrix by crack deflections. Because of the uniformly distributed fine TiC particles, the bending strength of the liquid mixing processed composite was superior to that of the casting processed composite.

• 공업화학
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• 제35권3호
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• pp.260-265
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• 2024

반도체 웨이퍼 운반용 tray에 사용하기 위한 반도체 대전방지용 물질을 합성하기 위해 탄소나노튜브를 포함하는 폴리(메틸메타크릴레이트)(PMMA)와 폴리우레탄(PU)의 in-situ polymerization이 설계되고 진행되었다. 새롭게 합성된 복합체는 상업용 장치 제조 공정을 모방한 조건에서 열적특성과 전기전도성 특성을 평가하였다. 이들의 관련 성능을 비교한 결과, 탄소나노튜브를 함유하고 있는 PMMA와 PU 모두 탄소나노튜브 함량이 올라갈수록 열적인 특성이 향상되었으며, 전기전도성 역시 함량이 올라갈수록 증가하는 우수한 성능을 나타내었다. In-situ polymerization을 통한 복합체의 morphology는 FE-SEM을 통하여 확인한 결과 상용성이 우수한 상태로 확인되었다. 탄소나노튜브를 포함하는 PMMA와 PU 모두 반도체 대전방지용 물질로서 사용할 수 있는 우수한 표면저항 값인 10³ Ω/□의 특성 결과를 확인할 수 있었다.

• Journal of Welding and Joining
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• 제17권2호
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• pp.36-43
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• 1999

The effect of microstructure on the fracture toughness of multi pass weld metal has been investigated. The micromechanisms of fracture process are identified by in-situ scanning electron microscopy(SEM) fracture observation using single edge notched specimen. The notches of the in-situ fracture specimens were carefully located such that the ends of the notches were in the as-deposited top bead and the reheated weld metal respectively. The observation of in-situ fracture process for as-deposited top bead indicated that as strains are applied, microcracks are formed at the interfaces between soft proeutectoid ferrite and acicular ferrite under relatively low stress intensity factor. Then, the microcracks propagate easily along the proeutectoid ferrite phase, leading to final fracture. These findings suggest that proeutectoid ferrite plays an important role in reducing the toughness of the weld metal. On the other hand, reheated regions showed that the microcrack initiated at the notch tip grows along the localized shear bands under relatively high stress intensity factor, confirming that reheated area showing momogeneous and fine microstructure would be beneficial to the fracture resistance of weld metal.