• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.475-480
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• 2002

The reliability of the solder joint is affected by type and extent of the interfacial reaction between solder and substrates. Therefore, understanding of intermetallic compounds produced by soldering in electronic packaging is essential. In-based alloys have been favored bonding devices that demand low soldering temperatures. For photonic and fiber optics packaging, m-based solders have become increasingly attractive as a soldering material candidate due to its ductility. In the present work, the interfacial reactions between indium solder and bare Cu Substrate are investigated. For the identification of intermetallic compounds, both Scanning Electron Microscopy(SEM) and X-Ray Diffraction(XRD) were employed. Experimental results showed that the intermetallic compounds, such as Cu$_{11}$In$_{9}$ was observed for bare Cu substrate. Additionally, the growth rate of these intermetallic compounds was increased with the reaction temperature and time. We found that the growth of the intermetallic compound follows the parabolic law, which indicates that the growth is diffusion-controlled.d.

• 한국세라믹학회지
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• 제42권7호
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• pp.509-515
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• 2005

Interfacial reactions at LSGM electrolyte and NiO-GDC anode interfaces were thoroughly investigated with Environmental Scanning Electron Microscopy (ESEM-PHlLIPS XL-30) and Energy Dispersive X-ray (EDX-Link XL30). According to the analysis, serious reaction zone was observed at LSGM/NiO-GDC interface. It was found that the reaction layer was originated from the chemical reaction between NiO and LSGM. The reaction products were identified as La deficient form of LSGM based perovskite and Ni-La-O compounds such as LaSrGa$_{3}$O$_{7}$ and LaNiO$_{3}$ from the X-Ray Diffraction (XRD, Philips) analysis. According to the electrical characterization, interfacial layer was very electrically resistive which would be the cause of high internal resistance and low power generating characteristic of the unit cell.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.104-107
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• 2004

In this work, the blend of diglycidylether of bisphenol A (DGEBA) and modified polyurethane (PU) was prepared and characterized in the cure behaviors and mechanical interfacial properties. The N-benzylpyrazinium hexafluoroantimonate was used as a cationic initiator for cure, and the content of PU was varied within 0-20 phr. The cure behaviors and mechanical interfacial properties were studied by DSC, near­IR, and the critical stress intensity actor $(K_{IC})$ measurements. Also thermal stabilities were carried out by TMA and TGA analyses. As a result, the cure activation energy $(E_a)$ and the conversion $(\alpha)$ were slightly increased with increasing the PU content, and a maximum value was found at 10 phr PU. The mechanical interfacial properties measured from $K_{IC}$ showed a similar behaviors with the results of conversion. These results were probably due to the increase of the hydrogen bonding between the hydroxyl groups of DGEBA and isocyanate groups in PU.

• 대한기계학회논문집A
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• 제32권5호
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• pp.387-395
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• 2008

Stress distribution and interfacial debonding process at the interface between a rubber mold and a powder compact were analyzed during unloading under cold isostatic pressing. The Cap model proposed by Lee and Kim was used for densification behavior of powder based on the parameters involved in the yield function of general Cap model and volumetric strain evolution. Cohesive elements incorporating a bilinear cohesive zone model were also used to simulate interfacial debonding process. The Cap model and the cohesive zone model were implemented into a finite element program (ABAQUS). Densification behavior of powder was investigated under various interface conditions between a rubber mold and a powder compact during loading. The residual tensile stress at the interface was investigated for rubber molds with various elastic moduli under perfect bonding condition. The variations of the elastic energy density of a rubber mold and the maximum principal stress of a powder compact were calculated for several interfacial strengths at the interface during unloading.

• 한국안전학회지
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• 제38권2호
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• pp.1-7
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• 2023

Fiber-metal laminates (FMLs) and polymer matrix composites (PMCs) are formed in various ways. In particular, FMLs in which aluminum is laminated as a reinforced layer are widely used. Also, glass fiber-reinforced plastics (GFRPs) are generally applied as fiber laminates. The bonding interface layer between the aluminum and fiber laminate exhibits low strength when subjected to hot press fabrication in the event of delamination fracture at the interface. This study presents a simple method for strengthening the interface bonding between the aluminum metal and GFRP layer of FML composites. The surfaces of the aluminum interface layer are engraved with three kinds of patterns by using the laser machine before the hot press works. Furthermore, the effect of the laser patterns on the interfacial toughness is investigated. The interfacial toughness was evaluated by the energy release rate (G) using an asymmetric double cantilever bending specimen (ADCB). From the experimental results, it was shown that the strip type pattern (STP) has the most proper pattern shape in GFRP/Al FML composites. Therefore, this will be considered a useful method for the safety assessment of FML composite structures.

• Composites Research
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• 제16권3호
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• pp.25-31
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• 2003

본 연구에서는 화학적 표면처리에 따른 탄화규소(SiC)의 표면특성 변화가 탄소섬유강화 에폭시 복합재료의 열안정성 및 기계적 계면물성에 미치는 영향을 조사하였다. 표면처리된 탄화규소의 표면특성은 산ㆍ염기도와 접촉각 측정을 통하여 알아보았으며, 열안정성은 TGA를 이용하여 조사하였다. 제조한 복합재료의 기계적 계면물성은 ILSS와 임계세기인자($\textrm{K}_{IC}$), 그리고 critical strain energy release rate($\textrm{G}_{IC}$)를 통하여 고찰하였다. 실험 결과 산 처리된 SiC(A-SiC)는 미처리된 SiC(V-SiC)나 염기처리된 SiC(B-SiC)에 비하여 산도가 증가하였다. 접촉각 측정 결과, 화학적 표면처리는 극성요소의 증가에 기인하는 SiC의 표면자유에너지를 증가시켰다. 이와 같은 물성들은 양극산화로 향상되어졌는데, 이는 좋은 젖음성이 최종 복합재료의 섬유와 매트릭스 사이의 계면결합력을 증가시키는데 중요한 역할을 하기 때문인 것으로 사료된다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.215-216
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• 2004

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.138.3-138
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• 1998

• 폴리머
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• 제37권1호
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• pp.61-65
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• 2013

본 실험에서는, 양극산화 처리된 탄소섬유의 표면변화가 탄소섬유강화 복합재료의 기계적 계면특성을 통하여 살펴보았다. 양극산화 처리된 탄소섬유의 표면특성은 FTIR, XPS, 그리고 SEM을 통하여 알아보았다. 복합재료의 기계적 계면특성은 층간전단강도(interlarminar shear strength; ILSS)와 임계세기인자(critical stress intensity factor; $K_{IC}$) 그리고 임계변형속도에너지(critical strain energy release rate; $G_{IC}$)를 통하여 고찰하였다. 실험결과 양극산화에 의한 각각의 표면 처리된 탄소섬유는 표면특성의 변화를 가져오며, 복합재료의 ILSS, $K_{IC}$, 그리고 $G_{IC}$같은 기계적 계면특성은 탄소섬유의 양극산화를 통하여 향상되어진다. 전해질이 20% 황산/질산(3/1)일 때 다른 전해질보다 기계적 물성의 가장 큰 향상을 보였다. 이는 양극산화로 탄소섬유와 매트릭스 사이의 계면결합력의 향상때문이라 판단된다.

• 접착 및 계면
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• 제23권3호
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• pp.87-93
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• 2022

섬유와 기지 간 계면 특성을 분석하기 위해 일반적으로 접촉각을 활용하여 계산된 접착일을 활용한다. 접촉각 측정 방식으로 동적접촉각과 정적접촉각이 있으며, 본 논문에서는 보다 정확도가 높은 접촉각 측정 방법이 무엇인지 모색하였다. 각각 4가지 종류의 에폭시 수지와 유리섬유를 사용하였고, 유리섬유와 에폭시의 표면 에너지 결과를 기반으로 접착일, W_a을 계산하여 계면강도를 예측하였다. 접착일과 계면 전단강도는 이론상 비례관계이며, 이를 확인하기 위해 조성이 다른 에폭시와 유리섬유 간의 계면강도를 마이크로드롭렛 시험법을 이용하여 측정하였다. 정적접촉각 결과의 경우 접착일과 계면 전단강도 사이에는 일치하지 않는 경향을 보였다. 이는, 동적 접촉각 평가 방법은 정적접촉각에 비해, 드롭 크기에 따른 최소 표면적을 이루는 에러와 미니스커서에서 접선 측정에 따른 에러를 최소화할 수 있다는 점이다.