• 제목/요약/키워드: silicon carbide powder

검색결과 106건 처리시간 0.029초

산화물 결합 탄화규소 다공질 소재에 관한 연구 (Studies on the Oxide Bonded Silicon Carbide Porous Materials)

  • 이재춘;국일현
    • 한국세라믹학회지
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    • 제27권2호
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    • pp.179-186
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    • 1990
  • Silicon carbide porous materials used for hot gas filters were prepared using oxide binder. Chamotte, frit and H3PO4 were starting materials to synthesize the oxide binder for high temperature-use. Room temperature bending strength of the silicon carbide porous body was increased with increasing firing temprature or with the amount of the content of frit in the oxide binder. However, in the oxidebinder fired above132$0^{\circ}C$, cristobalite form of AlPO4 phase which undergoes rapid inversion became more prominent with increasing firing time. the average pore size of the silicon carbide filter materials was found to be about one third of the average grain size of the silicon carbide powder used in this study.

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탄화규소의 액상소결 (Liquid Phase Sintering of Silicon Carbide)

  • 김원중;김영욱
    • 한국세라믹학회지
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    • 제32권10호
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    • pp.1162-1168
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    • 1995
  • Systematic studies of the effects of additives and processing variables on the sintered density and the effect of crystalline forms of starting powders on the microstructure of pressureless sintered silicon carbide are described. Oxide additives were effective for the densification of SiC up to 96% of theoretical density at temperature as low as 185$0^{\circ}C$. Use of embedding powder increased the sintered density, up to 98% of theoretical density, by decreasing the weight loss during sintering. Composite type duplex microstructure has been developed due to the $\beta$longrightarrow$\alpha$ phase transformation of SiC by sintering at 185$0^{\circ}C$ and heat treatment at 195$0^{\circ}C$ for 1h.

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RF 유도 열플라즈마를 이용한 유기 용매로 부터의 탄화규소 나노 분말 합성 (Synthesis of Silicon Carbide Nano-Powder from a Silicon-Organic Precursor by RF Inductive Thermal Plasma)

  • 고상민;구상만;김진호;조우석;황광택
    • 한국세라믹학회지
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    • 제49권6호
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    • pp.523-527
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    • 2012
  • Silicon carbide (SiC) has recently drawn an enormous amount of industrial interest due to its useful mechanical properties, such as its thermal resistance, abrasion resistance and thermal conductivity at high temperatures. In this study, RF thermal plasma (PL-35 Induction Plasma, Tekna CO., Canada) was utilized for the synthesis of high-purity SiC powder from an organic precursor (hexamethyldisilazane, vinyltrimethoxysilane). It was found that the SiC powders obtained by the RF thermal plasma treatment included free carbon and amorphous silica ($SiO_2$). The SiC powders were further purified by a thermal treatment and a HF treatment, resulting in high-purity SiC nano-powder. The particle diameter of the synthesized SiC powder was less than 30 nm. Detailed properties of the microstructure, phase composition, and free carbon content were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), a thermogravimetric (TG) analysis, according to the and Brunauer-Emmett-Teller (BET) specific surface area from N2 isotherms at 77 K.

반응소결 탄화규소 세라믹스의 열물성과 기계적 특성에 미치는 SiC 크기의 영향 (Effect of the SiC Size on the Thermal and Mechanical Properties of Reaction-bonded Silicon Carbide Ceramics)

  • 권창섭;오윤석;이성민;한윤수;신현익;김영석;김성원
    • 한국분말재료학회지
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    • 제21권6호
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    • pp.467-472
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    • 2014
  • RBSC (reaction-bonded silicon carbide) represents a family of composite ceramics processed by infiltrating with molten silicon into a skeleton of SiC particles and carbon in order to fabricate a fully dense body of silicon carbide. RBSC has been commercially used and widely studied for many years, because of its advantages, such as relatively low temperature for fabrication and easier to form components with near-net-shape and high relative density, compared with other sintering methods. In this study, RBSC was fabricated with different size of SiC in the raw material. Microstructure, thermal and mechanical properties were characterized with the reaction-sintered samples in order to examine the effect of SiC size on the thermal and mechanical properties of RBSC ceramics. Especially, phase volume fraction of each component phase, such as Si, SiC, and C, was evaluated by using an image analyzer. The relationship between microstructures and physical properties was also discussed.

시알론을 첨가한 탄화규소 세라믹스의 제조 (Preparation of Silicon Carbide with Sialon)

  • 이종국;박종곤;이은구;김환
    • 한국세라믹학회지
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    • 제37권3호
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    • pp.247-255
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    • 2000
  • Silicon carbide with sialon was prepared by hot pressing and transient liquid-phase sintering, and the effects of sintering atmosphere and starting phases on their microstructural characteristics were investigated. The sintered SiC with Sialon composition(Y2O3, AlN, Si3N4) in argon atmosphere had high sintered density and large aspect ratio. But sintered specimens in nitrogen atmosphere showed low aspect ratio and small grian size, becuase of the retardation of phase transformation and grain growth. Addition of Y-Sialon powder to SiC also retarded the phase transformation to ${\alpha}$-SiC from ${\beta}$-SiC and densification. The SiC specimen prepared from the starting ${\beta}$-SiC powder with Sialon composition(Y2O3, AlN, Si3N4) showed the highest fracture toughness about 6.0 MPa$.$m1/2.

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탄화왕겨, 제지슬러지, 커피찌거기 및 실리카 혼합물로부터 탄화규소 결정체 합성 (SiC aggregates synthesized from carbonized rice husks, paper sludge, coffee grounds, and silica powder)

  • 박경욱;윤영훈
    • 한국결정성장학회지
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    • 제29권2호
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    • pp.45-49
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    • 2019
  • 본 연구에서는, 탄소성분으로서 탄화왕겨, 제지슬러지, 커피찌꺼기와 실리카 분말로부터, 비교적 미세한 탄화규소 결정질 응집체를 합성하였다. 탄소성분들과 실리카의 혼합물로부터 탄화규소 응집체를 얻기 위한 주요 반응물질은 열탄화환원 반응에 의해 생성된 일산화규소 기체로 추정되었다. 탄화왕겨, 제지슬러지, 커피찌꺼기와 실리카 분말의 혼합물로부터 열탄화환원반응법을 거쳐 생성된 탄화규소 결정질 응집체들에 대한 XRD 회절패턴으로부터 결정상을 분석하였고, FE-SEM과 FE-TEM을 통한 미세구조, 결정구조 분석이 이루어졌다. 탄화왕겨, 제지슬러지, 그리고 실리카 분말의 시료의 경우, XRD 분석에서는 $35^{\circ}$ 부근의 (111) peak은 비교적 높은 강도를 나타내었다. 탄화왕겨, 제지슬러지, 커피찌꺼기와 실리카 분말의 혼합물로부터 합성된 시료들에 대해 FE-SEM 관찰을 통하여 $1{\mu}m$ 이하의 미세입자들을 관찰하였으며, TEM 측정 결과에서는 탄화규소 결정질상의 (110) 회절패턴들을 확인하였다.

수성 알루미나/탄화규소 슬러리의 동결주조와 층상복합체의 제조: (I) 슬러리의 분산과 유동성 (Freeze Casting of Aqueous Alumina/Silicon Carbide Slurries and Fabrication of Layered Composites: (I) Dispersion and Rheology of Slurries)

  • 양태영;조용기;김영우;윤석영;박홍채
    • 한국세라믹학회지
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    • 제45권2호
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    • pp.99-104
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    • 2008
  • Zeta potential, sedimentation bulk density and rheology in the dispersion system have been studied in terms of solid loading (40-55 vol%), and types of additives. Ammonium polymethacrylate, glycerol, ethoxylated acetylenic diol, and polyvinyl alcohol have been used as the dispersant, cryo-protectant, surfactant, and binder, respectively. Sedimentation density greatly increased upon adding dispersant; the effect was more pronounced with ionic alumina suspension compared with covalent silicon carbide. With further addition of cryo-protectant and surfactant to dispersant, the sedimentation density increased somewhat. The suspension viscosity generally behaviored in an opposite manner to the sedimentation density, i.e., high sedimentation gave low high-shear viscosity, indicative of low order structure formation in the suspended particles. Shear rate rheology in shear rate of $2-300\;sec^{-1}$ showed a shear thinning and its onset began at similar shear rate (${\sim}100\;sce^{-1}$), regardless of solid loading.

RF 열플라즈마를 이용한 TEOS로 부터의 SiC 나노분말 합성 (Synthesis of SiC Nano-powder from TEOS by RF Induction Thermal Plasma)

  • 고상민;구상만;김진호;김지호;변명섭;황광택
    • 한국세라믹학회지
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    • 제48권1호
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    • pp.1-5
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    • 2011
  • Silicon carbide (SiC) has recently drawn an enormous industrial interest because of its useful mechanical properties such as thermal resistance, abrasion resistance and thermal conductivity at high temperature. RF Thermal plasma (PL-35 Induction Plasma, Tekna CO., Canada) has been utilized for synthesis of high purity SiC powder from cheap inorganic solution (Tetraethyl Orthosilicate, TEOS). It is found that the powders by thermal plasma consist of SiC with free carbon and amorphous silica ($SiO_2$) and, by thermal treatment and HF treatment, the impurities are driven off resulting high purity SiC nano-powder. The synthesized SiC powder lies below 30 nm and its properties such microstructure, phase composition, specific surface area and free carbon content have been characterized by X-ay diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric (TG) and Brunauer-Emmett-Teller (BET).

Bend Deformation Behavior of Silicon Carbide Reticulated Porous Ceramics

  • Zhu, Xinwen;Sakka, Yoshio;Tan, Shouhong;Jiang, Dongliang
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.608-609
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    • 2006
  • The deformation behavior under three-point bend test was found to depend on the loading uniformity and the macrostructure for SiC reticulated porous ceramics (RPCs). However, this dependence of loading uniformity is alleviated by improved macrostructure with fewer flaws and clogged pores. Even, this dependence becomes less important as the struts become thicker and stronger. The bend result of RPCs with highly uniform macrostructure is in excellent agreement with the GA (Gibson and Ashby) model, but the one with un-uniform macrostructure deviates from the GA model, suggesting that the macrostructure plays an important role in deformation behavior of RPCs under bend.

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