본 연구는 탄소 기반 필러인 탄소나노튜브 (Carbon nanotube, CNT), 탄소 섬유 (Carbon fiber, CF) 와 중공유리구체 (Hollow glass microsphere, HGM)를 혼입한 전도성 복합재료가 다양한 열화 상황 에 노출된 이후의 발열성능을 조사하고 분석하였다. 대부분 상황에서 시멘트 기반의 재료들은 질산 및 황산의 침투 또는 동결융해와 같은 다양한 자연적 열화상황에 노출되게 된다. 본 연구는 기존의 이러 한 한계를 극복하고자 HGM, 전도성 필러를 혼입한 전도성 복합재료를 제조하였고, 물리적·전기적 및 열적 특성을 조사하였다. 모든 시편에서 HGM의 혼입은 시편의 밀도와 열 전도도를 감소시켰으며, 다 량의 혼입은 강도와 전기 전도도를 감소시키는 결과를 관찰할 수 있었다. 그러나 적정량의 혼입은 오 히려 전기 전도도를 향상시키는 결과를 확인할 수 있었으며, 반복적인 발열 실험에서의 성능 유지 또 한 미혼입 시편에 비하여 상대적으로 뛰어난 것을 관찰할 수 있었다. 이러한 HGM의 혼입에 대한 영 향을 더욱 자세하게 분석하기 위하여 수은압입법, 주사전자현미경, 제타전위 및 라만분광법 등의 분석 이 수행되었다.

다양한 원인으로 콘크리트 구조물에 하중이 작용되며, 이에 대한 적절한 대응이 이루어지지 않으면 구조물에 열화가 발생하고, 붕괴와 같은 대규모 재난을 초래할 수 있다. 구조물에 발생하는 하중을 감 지하는 연구는 지속적으로 이루어지고 있지만, 안전성 모니터링을 위한 혁신적인 시스템에는 여전히 부족함이 존재한다. 탄소나노튜브/폴리우레탄 복합체는 다양한 공학 분야에서 구조물 건전성 모니터링 을 위한 센서로 활용되어 센싱 효과가 뛰어난 것으로 알려져 있다. 따라서 본 연구에서는 다양한 공학 분야에서 구조물 건전성 모니터링 센서로 활용되고 있는 탄소나노튜브/폴리우레탄 복합체를 제작하여 모니터링 시스템을 개발하였다. 다양한 하중에 대한 센싱 성능을 파악하기 위해 인장, 압축, 충격 시험 을 진행하였고, 동시에 센서의 전기적 변화를 분석하였다. 추가적으로 본 센서가 구조물 표면에 적용 됨에 따라 온도, 습도와 같은 환경적 영향성을 분석하여 활용 가능성을 평가하였다. 또한, 최대 48행, 48열의 다중 계측이 가능한 IoT 기반 다중 모니터링 시스템을 개발하고, 이를 구조물에 적용된 센서 와 연계하여 스마트 모니터링 시스템으로서의 성능을 평가하였다. 이를 통해 탄소나노튜브/폴리우레탄 복합체 기반 센서는 구조물 하중 감지 시스템으로 활용이 가능할 것으로 판단되었다.

To improve the thermophysical properties of Al alloy for thermal management materials, the Cu-coated carbon fibers (CFs) were used as reinforcement to improve the thermal conductivity (TC) and the coefficient of thermal expansion (CTE) of Al-12Si. The CFs reinforced Al matrix (CFs/Al) composites with different CFs contents were prepared by stir casting. The effects of the CFs volume fraction and Cu coating on the microstructure, component, TC and CTE of CFs/Al composites were investigated by scanning electron microscopy with EDS, X-ray diffraction, thermal dilatometer and thermal dilatometer. The results show that the Cu coating can effectively improve the interface between CFs and the Al-12Si matrix, and the Cu coating becomes Al2Cu with Al matrix after stir casting. The CFs/Al composites have a relative density greater than 95% when the volume fraction of CFs is less than 8% because the CFs uniform dispersion without agglomeration in the matrix can be achieved by stir casting. The TC and CTE of CFs/Al composites are further improved with the increased CFs volume fraction, respectively. When the volume fraction of CFs is 8%, the CFs/Al composite has the best thermophysical properties; the TC is 169.25 W/mK, and the CTE is 15.28 × 10– 6/K. The excellent thermophysical properties of CFs and good interface bonding are the main reasons for improving the thermophysical properties of composites. The research is expected to improve the application of Al matrix composites in heat dissipation neighborhoods and provide certain theoretical foundations.

Recently, carbon composites have been applied to various fields. However, carbon composites have not been applied to the fishing vessel field due to its structure standards centered on glass composites. In this study, a structural strength evaluation study was conducted for the application of carbon composites in the fishing vessel field. Hull minimum thickness verification test and hull joint verification test were conducted. Compared to glass composites, the verification was based on equivalent or better performance. The results show that carbon composites can reduce the weight by 20% compared to glass composites. For hull joints, it was necessary to increase the thickness of the joint seam by the thickness of the hull to apply carbon composite. Through this study, a standard for the application of carbon composites to fishing vessel can be established.

In this work, we investigated a modern combined processing technique for the synthesis of lightweight superhard composites based on boron–carbon. We used traditional B4C with precipitates of free graphite and Al powder as initial materials. In the first stage, the composites were fabricated by the self-propagating high-temperature synthesis (SHS) with the subsequent hot pressing of the compound. Further, by the disintegration and attrition milling, the ultrafine-grained powder was obtained. We used HCl and HNO3 acids for the chemical leaching of the powder to remove various impure compounds. At the last stage, a solid composite was obtained by the spark plasma sintering (SPS) method under nitrogen pressure. The main feature of this approach is to implement different synthesis techniques and chemical leaching to eliminate soft phases and to obtain superhard compounds from low-cost materials. The phases were studied by X-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. The composites compacted by the SPS method contained superhard compounds such as B13C2, B11.7C3.3, and c-BN. The fabricated composite has an ultrafine-grained microstructure. Using a Berkovich indenter, the following nanohardness results were achieved: B13C2 ~ 43 GPa, c-BN ~ 65 GPa (all in Vickers scale) along with a modulus of elasticity ranging between ~ 400 GPa and ~ 450 GPa.

Carbon/carbon composites are widely used in re-entry engineering applications thanks to their excellent mechanical properties at high temperatures, but they are easily oxidized in the oxygenated atmosphere. It is important to research their residual mechanical properties influenced by oxidation behaviour, in order to ensure the in-service safety. A microscale degradation model is proposed to predict the oxidation behavior based on the mass conservation and diffusion equations, the derived equivalent steady recession rate of composite is employed to evaluate the residual mechanical properties of the oxidized composite theoretically. A numerical strategy is proposed to investigate the oxidation mechanism of this composite. The differences in the degradation rate between the fiber and the matrix resulted in the steady state and an unchanged shape of the front. Residual mechanical properties of composite with three different domains of oxidation were simulated with a multiscale coupled model. The numerical results demonstrated that the mechanical properties of this composite decreased by 24–32% after oxidation for 30 min at 850 °C. Oxidation also caused the stress redistribution inside components, with the stress concentration diminishing their load-bearing capacity. The local areas of increased stress in the pyrocarbon matrix provided new ways for diffusion of oxygen into the pyrocarbon matrix and fibers.

To develop a high capacity lithium secondary battery, a new approach to anode material synthesis is required, capable of producing an anode that exceeds the energy density limit of a carbon-based anode. This research synthesized carbon nano silicon composites as an anode material for a secondary battery using the RF thermal plasma method, which is an ecofriendly dry synthesis method. Prior to material synthesis, a silicon raw material was mixed at 10, 20, 30, 40, and 50 wt% based on the carbon raw material in a powder form, and the temperature change inside the reaction field depending on the applied plasma power was calculated. Information about the materials in the synthesized carbon nano silicon composites were confirmed through XRD analysis, showing carbon (86.7~52.6 %), silicon (7.2~36.2 %), and silicon carbide (6.1~11.2 %). Through FE-SEM analysis, it was confirmed that the silicon bonded to carbon was distributed at sizes of 100 nm or less. The bonding shape of the silicon nano particles bonded to carbon was observed through TEM analysis. The initial electrochemical charging/ discharging test for the 40 wt% silicon mixture showed excellent electrical characteristics of 1,517 mAh/g (91.9 %) and an irreversible capacity of 133 mAh/g (8.1 %).

With a strive to develop light-weight material for automotive and aerospace applications, aluminum-based hybrid nanocomposites (AHNCs) were manufactured utilizing the compocasting approach in this study. Chopped carbon fibers (CFs) are reinforced along with different weight fractions of nanoclay (1–5%) in the matrix of AA6026 forming AHNCs. The AHNCs specimens were examined by microstructural analysis, mechanical characterization, fatigue, and corrosion strength as per ASTM guidelines. Electroless plating method is adopted for coating CFs with copper to improve the wettability with matrix. SEM pictures of manufactured composites reveal thin inter-dendritic aluminum grains with precipitate particle of eutectic at intergranular junctions, as well as nanoclay particles that have precipitated in the matrix. Tensile strength (TS) rises with inclusion of nanoclay up to a maximum of 212.46 MPa for 3% nanoclay reinforcement, after which the TS is reduced due to non-homogeneity in distribution, agglomeration and de-bonding of nanoparticles. Similarly, micro-hardness increases with addition of 3% nanoclay after which it decreases. Higher energy absorption was achieved with 3% nanoclay reinforced hybrid and a significant improvement in flexural strength was obtained. With addition of both CFs and nanoclay, the fatigue strength of the hybrid composite tends to increase due to flexible CFs and high surface area nanoclays which strengthen the grain boundaries until 3% addition. Addition of nanoclay lowers the corrosion rate with nanoclays filling the crevices and voids in the matrix.

In this study, we have fabricated the phenolic resin (PR)/polyacrylonitrile (PAN) blend-derived core-sheath nanostructured carbon nanofibers (CNFs) via one-pot solution electrospinning. The obtained core-sheath nanostructured carbon nanofibers were further treated by mixed salt activation process to develop the activated porous CNFs (CNF-A). Compared to pure PAN-based CNFs, the activated PR/PAN blend with PR 20% (CNF28-A)-derived core-sheath nanostructured CNFs showed enhanced specific capacitance of ~ 223 F g− 1 under a three-electrode configuration. Besides, the assembled symmetric CNF28-A//CNF28-A device possessed a specific capacitance of 76.7 F g− 1 at a current density of 1 A g− 1 and exhibited good stability of 111% after 5,000 galvanostatic charge/discharge (GCD) cycles, which verifies the outstanding long-term cycle stability of the device. Moreover, the fabricated supercapacitor device delivered an energy density of 8.63 Wh kg− 1 at a power density of 450 W kg− 1.

Renewed interest in the reinforced carbon graphite composites has intrigued the community in the advanced materials fields. In this work, we present a simple carbon nanofibers reinforced carbon graphite composites synthetic method by incorporating mixture of coal tar pitch, synthetic graphite, pitch coke and the dispersion liquid of carbon nanofibers via liquid-phase mixing process. The impact of carbon nanofiber utilization on the microstructures and mechanical properties of carbon graphite composites are studied systematically. The covalent surface modification of carbon nanofibers effectively improves its microstructure and thereby promotes the carbon graphite composites’ dispersion behavior. We propose that a small amount of carbon nanofibers could promote the carbonization process of carbon graphite composites, facilitating the densification of carbon graphite composites and reducing the undesired open porosity. The amount of 0.7 wt % of carbon nanofiber concentration allows the enhancement of bend and compressive strength of carbon graphite composites up to 36.50 MPa and 60.46 MPa, increased by 167.9% and 146.9% compared with the pure carbon graphite composite, respectively. Our findings can be rationalized due to the improvement in the mechanical strength of carbon graphite composites could be attributed due to pull-out of carbon nanofibers from the matrix and bridging effect across the crack pores within the matrix.

In this paper, the mechanical properties according to the rCF weight percent(10, 20, 30, 40, 50wt%) of the rCFRP specimen were evaluated and analyzed. First, to prepare rCFRP specimens, pellets were prepared according to the type of weight percent, and rCFRP tensile specimens according to ASTM D638 were prepared using an injection molding machine. Tensile tests were performed on each of 10 specimens according to weight percent conditions, and tensile strength and modulus of elasticity were calculated. For a detailed analysis of the correlation between the internal structure of the specimen and the mechanical properties, the weight percent to the constituent materials of the rCFRP specimen was calculated using mCT and used for the analysis of mechanical properties. For a more detailed analysis, a detailed analysis of the mechanical properties of rCFRP was performed through the fracture surface analysis of the specimen using FE-SEM.

The utilization of carbonaceous reinforcement-based polymer matrix composites in structural applications has become a hot topic in composite research. Although conventional carbon fiber-reinforced polymer composites (CFRPs) have revolutionized the composite industry by offering unparalleled features, they are often plagued with a weak interface and lack of toughness. However, the promising aspects of carbon fiber-based fiber hybrid composites and hierarchical composites can compensate for these setbacks. This review provides a meticulous landscape and recent progress of polymer matrixbased different carbonaceous (carbon fiber, carbon nanotube, graphene, and nanodiamond) fillers reinforced composites’ mechanical properties. First, the mechanical performance of neat CFRP was exhaustively analyzed, attributing parameters were listed down, and CFRPs’ mechanical performance barriers were clearly outlined. Here, short carbon fiber-reinforced thermoplastic composite was distinguished as a prospective material. Second, the strategic advantages of fiber hybrid composites over conventional CFRP were elucidated. Third, the mechanical performance of hierarchical composites based on carbon nanotube (1D), graphene (2D) and nanodiamond (0D) was expounded and evaluated against neat CFRP. Fourth, the review comprehensively discussed different fabrication methods, categorized them according to performance and suggested potential future directions. From here, the review sorted out three-dimensional printing (3DP) as the most futuristic fabrication method and thoroughly delivered its pros and cons in the context of the aforementioned carbonaceous materials. To conclude, the structural applications, current challenges and future prospects pertinent to these carbonaceous fillers reinforced composite materials were elaborated.

Acrylonitrile–butadiene–styrene (ABS) terpolymer was compounded with short carbon fiber (CF) and carbon nanotube (CNT) using a micro-extruder followed by the injection molding process. Composite samples were fabricated with loading ratios of 20 wt.% CF and 0.1, 0.5 and 1.0 wt.% of CNT. Mechanical, electrical, thermo-mechanical, thermal, melt-flow, and structural investigations of ABS-based composites were conducted by performing tensile, impact, hardness, and wear tests, conductive atomic force microscopy (AFM), dynamic mechanical analysis (DMA), thermal gravimetric analysis (TGA), melt flow rate test (MFR), scanning electron microscopy (SEM) characterization techniques, respectively. According to mechanical test data of resultant composites including tensile and impact test findings, CNT additions led to the remarkable increase in tensile strength and impact resistance for CF reinforced ABS composites. The formation of synergy between CNT nanoparticles and CF was confirmed by electrical conduction results. The conductive path in ABS/CF composite system was achieved by the incorporation of CNT with different loading levels. SEM micrographs of composites proved that CNT nanoparticles exhibited homogeneous dispersion into ABS matrix for lower loadings.

In this present investigation, machinability studies on novel aluminum composite with hybrid reinforcements of copper-coated 4% carbon fibers (CFs) and 3% nanoclay in AA6026 matrix fabricated by compocasting method is performed. Step drill bit and multifaceted drill bit are used by adopting central composite design (CCD) in response surface methodology (RSM). The outcomes show that, with a rise in rotational speed surface irregularities, resultant force and material removal rate (MRR) intensifies, and with the additional rise in rotational speed, all the outputs decrease considerably. High MRR, resultant cutting force, and surface roughness are obtained with multifaceted carbide drills, compared with a step drill. Desirability function is used to maximize the MRR and minimize the resultant cutting forces considering the constant surface roughness of 3 μm. The optimal values are rotational speed of 1285 rpm, feed rate of 60 mm/min with the step drill bit, producing an MRR of 0.0439 kg/sec and a resultant cutting force of 185.818 N. The second-order empirical models are developed for outputs, which are fed into the non-traditional metaheuristic Evaporation Rate-based Water Cycle Algorithm (ER-WCA) therefore the lower objective value is achieved with step drill of 51.7421. It is found that using a step drill the machinability performance of this hybrid nanocomposite is well improved than the machining with other drill bits. This composite fulfills the norms of 2000/53/CE-ELV European environmental directives.

Rapid development of carbon nanotubes (CNTs) reinforced to polymer composites has been recently noticed in many aspects. In this work, the latest developments on fatigue and fracture enhancement of polymer composites with CNTs reinforcement with diverse methods are thoroughly compiled and systematically reviewed. The existing available researches clearly demonstrate that fatigue fracture resistance of polymer composites can be improved accordingly with the addition of CNTs. However, this work identifies an interesting research gap for the first time in this field. Based on the systematic reviewing approach, it is noticed that all previously performed experiments in this field were mostly focused upon studying one factor only at a time. In addition, it is also addressed that there were no previous studies reported a relationship or effect of one factor upon others during examining the fatigue fracture of carbon nanotubes. Moreover, there was no adequate discussion demonstrating the interaction of parameters or the influence of one parameter upon another when both were examined simultaneously. It is also realized that the scope of the conducted fatigue fracture studies of carbon nanotubes were mainly focused on microscale fatigue analysis but not the macroscale one, which can consider the effect of environment and service condition. In addition, the inadequacy of fatigue life predicting models via analytical and numerical methods for CNT-reinforced polymer composites have also been highlighted. Besides, barriers and challenges for future directions on the application of CNT-reinforced polymer composite materials are also discussed here in details.

Carbon fiber and its composites are increasingly used in many fields including defence, military, and allied industries. Also, surface quality is given due importance, as mating parts are used in machineries for their functioning. In this work, the turning process is considered for Carbon Fiber Reinforced Polymer (CFRP) composites by varying three important cutting variables: cutting speed, feed, and depth of cut. Correspondingly, the surface roughness is measured after the completion of turning operation. As well, a prediction model is created using different fuzzy logic membership function and Levenberg–Marquardt algorithm (LMA) in artificial intelligence. Later, the surface roughness values from the developed models are compared against the experimental values for its correlation and effectiveness in using different membership functions of fuzzy logic and ANN. Thus, the experimental results are analyzed using the effect graphs and it is presented in detail.