• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.31-34
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• 2004

Carbon nanofiber exhibits superior and often unique characteristics of mechanical, electrical chemical and thermal properties. In this study, For improvement of the mechanical properties of composites, carbon nanofiber reinforced hybrid composites was investigated. For the effect of dispersion, The dispersion methods of solution blending and mechanical mixing were used. The mixing of solution blending method was used using ultrasonic. Dispersion of carbon nanofiber was observed by scanning electron microscope (SEM). Mechanical properties were measured by universal testing Machine (UTM).

• Composites Research
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• 제13권1호
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• pp.50-60
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• 2000

본 연구는 섬유/입자 혼합금속복합재료의 강화기구를 분석하는 이론적 해석방법을 제시하였다. 혼합금속복합재료의 인장강도 및 탄성계수는 같은 보강재의 부피분율 가진 단섬유복합재료에 비해서 강도가 최대 20%까지 증가한다. 이러한 증가효과는 본 연구에서 새로이 제안된 클러스터 모델을 도입한 후 이에 따른 강화효과를 Modified Rule of Mixture을 적용하여 분석하였다. 해석결과 클러터구조는 인장강도에 대해서 섬유의 효율을 탄성계수에 대해서는 배향인자를 증가시키는 것으로 나타났다. 이론적 해석 결과는 $Al_2O_3$섬유/입자 예비성형체에 AC8A를 침투시켜 제조한 금속복합재료에 대한 실험결과와 비교되었으며 이를 통해 해석이론이 타당함을 확인하였다.

• 한국분말재료학회지
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• 제20권4호
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• pp.285-290
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• 2013

$Ti_2AlN$ composites are a laminated compounds that posses unique combination of typical ceramic properties and typical metallic(Ti alloy) properties. In this paper, the powder synthesis, SPS sintering, composite characteristics and machinability evaluation were systematically conducted. The random orientation characteristics and good crystallization of the $Ti_2AlN$ phase are observed. The electrical and thermal conductivity of $Ti_2AlN$ is higher than that of Ti6242 alloy. A machining test was carried out to compare the effect of material properties on micro electrical discharge drilling for $Ti_2AlN$ composite and Ti6242 alloy. Also, mixture table as a kind of tables of orthogonal arrays was used to know how parameter is main effective at experimental design. Consequently, hybrid $Ti_2AlN$ ceramic composites showed good machining time and electrode wear shape under micro ED-drilling process. This conclusion proves the feasibility in the industrial applications.

• Elastomers and Composites
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• 제54권1호
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• pp.22-29
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• 2019

Chitosan-polyvinyl alcohol (PVA) -bamboo charcoal/silica (CS-PVA-BC/SI) hybrid fillers with compatibilized styrene-butadiene rubber (SBR) composites were fabricated by the interpenetrating polymer network (IPN) method. The structure and composition of the composite samples were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). The viscoelastic behaviors of the rubber composites and their vulcanizates were explored using a rubber processing analyzer (RPA) in the rheometer, strain sweep and temperature sweep modes. The storage and loss moduli of SBR increased significantly with the incorporation of different hybrid fillers, which was attributed to the formation of an interphase between the hybrid fillers and rubber matrix, and the effective dispersion of the hybrid fillers. The mechanical properties (hardness, tensile strength, oxygen transmission rate, and swelling rate) of the composite samples were characterized in detail. From the results of the mechanical test, it was found that BC-CS-PVA0SBR had the best mechanical properties. Therefore, the BC-CS-PVA hybrid filler provided the best reinforcement effects for the SBR latex in this research.

• 대한기계학회논문집
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• 제19권4호
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• pp.968-980
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• 1995

Al/Al$_{2}$O$_{3}$/C hybrid metal matrix composites are fabricated by the direct squeeze infiltration method. From the microstructure of Al/Al$_{2}$O$_{3}$/C composites, uniform distribution of reinforcements and good bondings are found. Optimum processing conditions for preforms and squeeze castings are suggested. Mechanical properties, such as elastic modulus, elongation, 0.2% offset yield strength and ultimate tensile strength are obtained. Through the abrasive were test and wear surface analsis, wear behavior and its mechanism of AC2B aluminum and Al/Al$_{2}$O$_{3}$/C composites can be characterized under various sliding speed conditions. Tensile strenght elongation of Al/Al$_{2}$O$_{3}$/C composites are decreased with increasing the addition of carbon fiber. On the contrary, elastic modulus of Al/Al$_{2}$O$_{3}$/C composites is slightly improved compared with that of the unreinforced matrix alloy. The addition of carbon fiber to al/al$_{2}$O$_{3}$/C composites gives rise to improvement of the wear resistance. Specially, carbon chopped fibers play an important role in interfering sticking between the counter material and metal matirix composites. Al/Al$_{2}$O$_{3}$/C composites are suitable to high speed due to solid lubication of carbon. And wear model of Al/Al$_{2}$O$_{3}$/C composites is suggested by the examination of worn surfaces.

• Composites Research
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• 제13권1호
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• pp.78-88
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• 2000

하이브리드 복합재료는 구조용으로 개발되어 여러 분야에서 응용되고 있으며, 특히 항공산업, 우주산업, 스포츠레저산업, 자동차산업 등에서 그 응용 분야를 확대하고 있다. 섬유 보강 고분자 복합재료는 비강도, 비강성이 높으며, 물리 화학적 성질, 동적 특성, 트라이볼로지 특성 등이 우수하여 고부가가치를 가지는 부품이나 성형물을 생산할 수 있다. 이러한 하이브리드 복합재료는 치차, 베어링, 캠, 씨일 등의 마찰부품으로도 사용가능성이 매우 높으며, 하이브리드 복합재료의 구조를 적절히 설계함으로써 일정한 하중에 견디며, 마찰마모특성이 뛰어난 바이오미메틱 재료로서 사용될 수 있다. 복합재료의 마찰 및 마모 특성을 규명하기 위하여 마찰 및 마모시험기를 설계하여 제작한 후 일방향 섬유복합재료의 마찰 및 마모 성질을 측정하였다. 탄소섬유, 아라미드섬유, 유리섬유 등이 포함된 일방향 복합재료의 트라이볼로지 특성을 규명하여 이를 바탕으로 최소마모율이 예상되는 하이브리드 복합재료의 구조를 제안하기 위하여 유리섬유복합재료, 탄소섬유 복합재료, 아라미드섬유 복합재료의 마찰 및 마모특성을 측정하였다. 그 결과 섬유복합재료의 마찰 및 마모성질은 섬유의 배향과 활주속도 및 보강섬유의 종류에 따라 변화함을 알았다. 각 시편에 대한 실험결과를 분석하여, 탄소섬유와 아라미드섬유가 하이브리드화 된 복합재료의 구조를 제안하고 그 시편을 제작하여 실험하였고 결과를 분석하였다.

• Composites Research
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• 제18권3호
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• pp.1-6
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• 2005

탄소나노섬유는 기계적, 전기적, 화학적, 열적 성질 등의 우수하고, 독특한 특성을 가진다. 이러한 탄소나노섬유의 우수한 물성에도 불구하고, 탄소나노섬유가 강화된 고분자 복합재료의 물성은 비례적으로 증가하지 않는다. 이러한 원인은 탄소나노섬유가 고분자 재료 내에 고루 분산되지 못하기 때문이다. 본 연구에서는 복합재료의 기계적 물성을 향상시키기 위해, 탄소나노섬유가 강화된 하이브리드 복합재료에 대한 연구를 수행하였다. 탄소나노섬유의 고른 분산을 위해, 초음파 분산장치를 이용한 용융 혼합방법을 이용하였고, 전자현미경(SEM)을 통해 탄소나노섬유의 분산정도를 확인하였으며, 만능시험기(UTM)를 이용하여 탄소나노섬유가 강화된 하이브리드 복합재료의 기계적 물성을 평가하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.67-70
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• 2000

This study was performed to investigate the material behavior of hybrid thermoplastic composites contained glass fiber and calcium carbonate. The composite was prepared with each combination ratio of calcium carbonate, and the content of glass fiber was fixed with 10% by weight. In order to investigate the material behavior for various combination ratio, tension test, flexural test, and impact test were performed. Microscopic observation were conducted to examine the fractured surface of specimen for tension test. And the material behavior of the hybrid thermoplastic composite immersed in salt water with definite time was investigated.

• Structural Engineering and Mechanics
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• 제52권5호
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• pp.857-873
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• 2014

Structural behaviors of a sustainable hybrid column with the ultra high performance cementitious composites (UHPCC) permanent form under compression and flexure were studied. Critical state and failure stage characters are analyzed for large and small eccentricity cases. A simplified theoretical model is proposed for engineering designs and unified formulas for loading capacity of the hybrid column under compression and flexure loads are derived, including axial force and moment. Non-linear numerical analysis is carried out to verify the theoretical predictions. The theoretical predictions agree well with the numerical results which are verified by the short hybrid column tests recursively. Compared with the traditional reinforced concrete (RC) column, the loading capacity of the sustainable hybrid column is improved significantly due to UHPCC confinements.

• Steel and Composite Structures
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• 제22권1호
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• pp.13-24
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• 2016

In the present paper, glass fibers are substituted partially with monofilament fishnet and polyester matrix for making the composites. The composite specimens were prepared in accordance with ASTM for analyzing the flexural strength and dynamic mechanical properties. Furthermore, machinability revealed the interaction of glass fiber and partial substituted monofilament fishnet fiber with the matrix. Fiber pullouts on the fractured specimen during the physical testing of the composites are also investigated by COSLAB microscope. The results reveal that the fishnet based composites have appreciably higher flexural properties. Furthermore, the glass fiber, woven roving and fishnet composite has more storage modulus and significant mechanical damping. The composite specimens were fabricated by hand lay-up method. Hence, these composites are the possible applications to develop the value added products. The results of this study are presented.