• Title/Summary/Keyword: c/c composite

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A study on the wear resistance of Ni-SiC composite plating (Ni-SiC 복합도금층의 내마모성에 관한 연구)

  • 김성호;한혜원;장현구
    • Journal of the Korean institute of surface engineering
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    • v.29 no.1
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    • pp.26-35
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    • 1996
  • The Ni-SiC composite plating was performed in a Watt nickel solution and the wear resistance of the composite layer was studied on a pin-on-flat type wear tester. The volume losses and friction coefficients were measured. It was found that the quantity of SiC powder in the composite layers was affected by SiC concentration, pH, temperature, and agitation speed in the Watt nickel solution. The hardness and wear resistance of the coatings increased with SiC content. The quantity of SiC powder in the coating from a nickel sulfamate solution is larger than that of the Watt nickel solution, because the amount of nickel ions absorbed on the SiC powder in the nickel sulfamate solution is greater than that in the Watt's solution.

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Characterization of the Ni and Ni-Cr Porous Metal Reinforced AC4C Matrix Composites Fabricated by Squeeze Casting (용탕단조법에 의한 Ni, Ni-Cr 다공질 발포금속 강화 AC4C 합금기 복합재료에 관한 연구)

  • Kim, Eok-Soo
    • Journal of Korea Foundry Society
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    • v.25 no.2
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    • pp.80-87
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    • 2005
  • The microstructure and mechanical property of the Ni and Ni-Cr porous metal reinforced AC4C matrix composites fabricated by squeeze casting were investigated. In this study Ni, Ni-Cr porous metals which are estimated to be easy to fabricate by squeeze casting are used as strengtheners for composite materials. As a matrix material, Al-7wt.%Si-0.3wt.%Mg(AC4C) has been used. In case of Ni/AC4C and Ni-Cr/AC4C composite, $750^{\circ}C$ melt temperature and minimum 25MPa squeezing pressure are needed to produce sound composite materials. The observation of interfacial reaction zone at various heat treatment condition shows that atsolutionizing temperature of above $520^{\circ}C$, the interfacial reaction zone increases proportionally with heat treatment time and the reaction products formed by interfacial reactions are mainly composed by $Al_{3}Ni$ and $Al_{3}Ni_{2}$ phases.

The Performance Evaluation of C/SiC Composite for Rocket Propulsion Systems (추진기관용 C/SiC 복합재료의 특성 평가)

  • Kim, Yun-Chul
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.433-438
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    • 2009
  • The main objective of this research effort is to develop the performance of C/SiC composites manufactured by LSI (Liquid Silicon Infiltration) method for solid and liquid rocket propulsion system and ensure the performance analysis technique. The high performance and reliability of C/SiC composite are proved for solid and liquid rocket propulsion system. And the performance analysis technique related to mathematical ablation model is originated.

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Preparation of Carbon Composite with High Oxidation Resistance by MoSi2 Dispersion

  • Goto, S.;Kodera, M.;Toda, S.;Fujimori, H.;Ioku, K.
    • The Korean Journal of Ceramics
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    • v.5 no.2
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    • pp.115-118
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    • 1999
  • Carbon composites with $MoSi_2$ dispersion were prepared by hot-pressing at $1700^{\circ}C$ under 30 MPa for 1 h using polysilazance as binding material. The composites consisted of C, $Mo_{4.8}Si_3C_{0.6}$ and SiC. Bulk density and porosity of the carbon composites with 10 vol% $MoSi_2$ was 1.8g.$\textrm{cm}^{-3}$ and 34%, respectively. This composite was oxidized about 0.05mm from the surface of the carbon composite after oxidation test at $1500^{\circ}C$ for 10h in air. Formation of the $SiO_2$ glass layer was observed by SEM. When this composite suffered damage in the coating layer, it had hardly farther oxidation because of its self-repairing property. The composite prepared in this study indicated good oxidation resistance.

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Synthesis of Si-SiC-CuO-C Composite from Silicon Sludge as an Anode of Lithium Battery (실리콘 슬러지로부터 리튬전지(電池) 음극용(陰極用) Si-SiC-CuO-C 복합물의 합성(合成))

  • Jeong, Goo-Jin;Jang, Hee-Dong;Lee, Churl-Kyoung
    • Resources Recycling
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    • v.19 no.4
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    • pp.51-57
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    • 2010
  • As a recycling of Si sludge from Si wafer process, a Si-SiC-CuO-C composite material was synthesized and investigated as an anode material for lithium batteries. The Si sludge consisted of Si, SiC, machine oil, and metallic impurities. The oil and metal impurities was removed by organic washing, magnetic separation, and acid washing. The Si-SiC-CuO-C composite from the recovered Si-SiC mixture was prepared by high-energy mechanical milling. According to the electrochemical tests such as charge-discharge capacity and cycling behavior, it showed the improved cycle performance. The SiC and CuO-related phases were presumed to restrain the volume expansion of the anode and Fe, however, should be removed below 10 ppm prior to synthesis of the composite because it caused the capacity loss of the active material itself.

Study of Manufacturing Process and Properties of C/C Composites with Recycled Carbon Fiber Reinforced Plastics (리싸이클 CFRP 적용 C/C 복합재료 제조 및 특성 연구)

  • Kim, Seyoung;Han, In Sub;Bang, Hyung Joon;Kim, Soo-hyun;Seong, Young-Hoon;Lee, Seul Hee
    • Composites Research
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    • v.35 no.4
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    • pp.242-247
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    • 2022
  • This study has a different direction from the existing technology of applying recycled carbon fiber obtained by recycling waste CFRP to CFRP again. A study was conducted to utilize recycled carbon fiber as a raw material for manufacturing a carbon/carbon (C/C) composite material comprising carbon as a matrix. First, it was attempted to recycle a commonly used epoxy resin composite material through a thermal decomposition process. By applying the newly proposed oxidation-inert atmosphere conversion technology to the pyrolysis process, the residual carbon rate of 1~2% was improved to 19%. Through this, the possibility of manufacturing C/C composite materials utilizing epoxy resin was confirmed. However, in the case of carbon obtained by the oxidation-inert atmosphere controlled pyrolysis process, the degree of oxygen bonding is high, so further improvement studies are needed. In addition, short-fiber C/C composite material specimens were prepared through the crushing and disintegrating processes after thermal decomposition of waste CFRP, and the optimum process conditions were derived through the evaluation of mechanical properties.

A Study on the Graded Ni-SiC Composite Coating by Electrodeposition (전해석출에 의한 단계적 Ni-SiC 복합코팅층 제조공정에 관한연)

  • 김선규
    • Journal of the Korean institute of surface engineering
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    • v.30 no.5
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    • pp.347-354
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    • 1997
  • Composite plating is a method of co-depositing fine particles of metallic, non-metallic compound or polymers in the plated layer to improve material properties such as were-resistance, lubrication, or corrosion resistance. Graded Ni-Sic composite coating were produced in this research. Prior to produce Graded Ni-SiC composite coatings, effects of particle size, particle content, pH of electrolyte, temperature, current density, stirring rate on the amount of SiC deposited in the Ni layer were investigated. By manipulating current density and plating time properties of these coating were evaluated by micro-indentation hardness test.

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Preparation and Characterization of Mesophase Pitches as a Matrix Precursor of Carbon Fiber Reinforced Carbon Composite (탄소/탄소 복합재 매트릭스 전구체로서의 메조페이스 핏치의 제조 및 특성에 관한 연구)

  • 정현진;임연수
    • Journal of the Korean Ceramic Society
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    • v.33 no.12
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    • pp.1387-1393
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    • 1996
  • A study on mesophase pitch as a matrix precursor of carbon fiber reinforced carbon (C/C) composite has been recently presented. This study is concerned with the production of mesophase pitch as matrix precursors for C/C composite from coal tar pitch. A commercial coal tar pitch was heat-treated at 25$0^{\circ}C$ for 2 hours to remove low molecular weight fraction from the pitch then increasing the temperature of the pitch to between 350~45$0^{\circ}C$ to produce mesophase pitch. The pitch was continuously stirred during this time and nitrogen gas was continuously bubbled through the pitch. Spherical and bulk mesophases were formed in the pitch after heat-treatment,. Parent and mesophae pitches were characterized by elemental analysis coke yield solubi-lity in tetrahydrofuran and hexane and an optical microscopy to measure the mesiophase content. It was neces-sary to produce C/C composite that a mesophase pitch with about 30-40 vol% mesophase spherulites can be infiltrated into a fiber preform without a filter effect as a matrix precursor conditions. This condition was satisfied with mesophase pitch heat treated at 40$0^{\circ}C$ for 2 hours. The other heat treatment conditions showed the nuclei of mesophase or bulk mesophae which were not satisfied with the matix precursor condition.

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Improvement of Mechanical Properties of P/M Processed $2XXX Al-SiC_w$ Composites ($2XXX Al-SiC_w$ 복합재료의 분말야금 제조와 기계적 성질 향상 연구)

  • 신기삼
    • Journal of Powder Materials
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    • v.2 no.3
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    • pp.238-246
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    • 1995
  • The purpose of this study is to establish powder metallurgy (P/M) fabrication processes for high performance 2XXX Al composites reinforced with SiC whiskers. Rapidly solidified 2XXX Al powders produced by commercial atomization technique were mixed with SiC whiskers. The results of mixing processes indicated that fluidized zone mixing technique was considerably effective for the large scale production of the mixture of Al powders and whiskers. In order to consolidate these $Al-SiC_w$ mixtures into $Al-SiC_w$ composite billets, a vacuum hot press was set up, and hot processing variables were investigated. Using the hot pressing temperature of $620^{\circ}C$ under the pressure of 50 MPa, good quality $Al-SiC_w$ composite billets having relatively homogeneous microstructure and sound Al/sic interfacial bonding were obtained. Composite billets were then extruded to bars having relatively homogeneous microstructures at the extrusion temperature of 450~500$^{\circ}C$ under the extrusion pressure of 700~ 1000 MPa. Mechanical properties of the extruded bars were found to be comparable with those of the composite processed by Advanced Composite Materials Corp. To improve mechanical properties of the composites, elimination of coarse intermetallic compounds, uniform distribution of reinforcements, and minimization of whisker breakage are suggested.

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Effect of Alumina Coating on Mechanical Properties of SiC Whisker Reinforced Silicon Nitrate Ceramic Composite

  • Lee, Ki-Ju;Xu, Jing-Wen;Hwang, Woon-Suk;Cho, Won-Seung
    • Corrosion Science and Technology
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    • v.6 no.1
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    • pp.24-28
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    • 2007
  • Alumina coated SiC whiskers were prepared by homogeneous precipitation of aluminum sulfate. The Si3N4 composites reinforced with coated SiC whiskers were fabricated by hot-pressing at $1800^{\circ}C$ for 2 h under an $N_{2}$ atmosphere of 0.1 MPa to examine the effects of coated whiskers on the mechanical properties of SiC whisker reinforced $Si_{3}N_{4}$ composite. By the addition of alumina coated SiC whiskers instead of as received ones, the fracture toughness of composite was about 6.7 $MPam^{1/2}$ which was slightly lower than as received SiC whisker reinforced composite. This result seems to be caused by the fact that the crack deflection and whisker pull-out were decreased. Thus, alumina coated SiC whiskers were considered to form relatively strong interface bond with $Si_{3}N_{4}$ matrix.