• Title/Summary/Keyword: SiSiC

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Growth of SiC film on SiNx/Si Structure (SiNx/Si 구조를 이용한 SiC 박막성장)

  • Kim, Gwang-Cheol;Park, Chan-Il;Nam, Gi-Seok;Im, Gi-Yeong
    • Korean Journal of Materials Research
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    • v.10 no.4
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    • pp.276-281
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    • 2000
  • Silicon carbide(SiC) films were grown on modified Si(111) surface with a SiNx in the NH$_3$surrounding. Thickness of SiC films was decreased with increasing of the nitridation time. Also, voids having crystal defects were removed at interface of SiC/Si according to growth parameters. SiC films were grown on SiNx/Si substrate of 100, 300 and 500nm thickness. SiC films were deposited along [111] direction and columnar grains of SiC crystal. The void-free film was observed in the interface of SiC/SiNx. This result suggests that fabrication of SiC devices are applied to SiNx replacing silicon oxide in SOI structure.

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Fabrication of SiC/SiC Composites by Reaction Sintering Process (반응소결법에 의한 SiC/SiC 복합재료의 제조)

  • Lee, S.P.;Yoon, H.K.;Kohyama, A.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.27-31
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    • 2001
  • Hi-Nicalon SiC fiber reinforced SiC composites (SiC/SiC) have been fabricated by the reaction sintering process. Braided Hi-Nicalon SiC fiber with double interphases of BN and SiC was used in this composite system. The microstructures and the mechanical properties of reaction sintered SiC/SiC composites were investigated through means of electron microscopies (SEM, TEM, EDS) and bending tests. The matrix morphology of reaction sintered SiC/SiC composites was composed of the SiC phases that the composition of the silicon and the carbon is different. The TEM analysis showed that the residual silicon and the unreacted carbon were finely distributed in the matrix region of reaction sintered SiC/SiC composites. Reaction sintered SiC/SiC composites also represented proper flexural strength and fracture energy, accompanying the noncatastrophic failure behavior.

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Mechanical and Electrical Properties of Si-SiC Fabricated Using SiC-C Composite Powders Synthesized by Sol-gel Process (Sol-gel 법으로 합성된 SiC-C 복합분말을 사용하여 제조된 Si-SiC의 기계적 특성 및 전기저항 특성)

  • Youn, Sung Il;Cho, Gyung Sun;Youm, Mi Rae;Lim, Dae Soon;Park, Sang Whan
    • Journal of the Korean Ceramic Society
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    • v.51 no.5
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    • pp.459-465
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    • 2014
  • In this study, Si-SiC composites were fabricated using a Si melt infiltration method using ${\beta}$-SiC/C composite powders synthesized by the carbothermal reduction of $SiO_2-C$ precursors made from a TEOS and a phenol resin. The purity of the synthesized SiC-C composite powders was higher than 99.9993 wt% and the average particle size varied from 4 to $6{\mu}m$ with increasing carbon contents of the $SiO_2-C$ precursors. It was found that the Si-SiC composites fabricated in this study consist of ${\beta}$-SiC and residual Si, without any trace of ${\alpha}$-SiC. The 3-point bending strengths of the fabricated Si-SiC composites were measured and found to be higher than 550 MPa, although the density of the fabricated Si-SiC composite was less than $2.9g/cm^3$. The bending strengths and the densities of the fabricated Si-SiC composites were found to decrease with increasing C/Si mole ratios in the SiC-C composite powders. The specific resistivities of the Si-SiC composites fabricated using the SiC-C composite powders were less than $0.018{\Omega}cm$. With increasing C content in the SiC-C composite powders used for the fabrication of Si-SiC composites, the specific resistivity of the Si-SiC composites was found to slightly increase from 0.0157 to $0.018{\Omega}cm$.

$\beta$-SiC Formation Mechanisms in Si Melt-C-SiC System (용융 Si-C-SiC계에서 $\beta$-SiC 생성기구)

  • 서기식;박상환;송휴섭
    • Journal of the Korean Ceramic Society
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    • v.36 no.6
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    • pp.655-661
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    • 1999
  • ${\beta}$-SiC formation mechanism in Si melt-C-SiC system with varying in size of carbon source was investigated. A continuous reaction sintering process using Si melt infiltration method was adopted to control the reaction sintering time effectively. It was found that ${\beta}$-SiC formation mechanism in Si melt-C-SiC system was directly affected by the size of carbon source. In the Si melt-C-SiC system with large carbon source ${\beta}$-SiC formation mechanism could be divided into two stages depending on the reaction sintering time: in early stage of reaction sintering carbon dissolution in Si melt and precipitation of ${\beta}$-SiC was occurred preferentially and then SIC nucleation and growth was controlled by diffusion of carbon throughy the ${\beta}$-SiC layer formed on graphite particle. Furthmore a dissolution rate of graphite particles in Si melt could be accelerated by the infiltration of Si melt through basal plane of graphite crystalline.

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Property Evaluation of Reaction Sintered SiC/SiC Composites Fabricated by Melt Infiltration Process (용융함침법에 의한 반응소결 SiC/SiC 복합재료의 특성 평가)

  • Lee, Sang-Pill;Shin, Yun-Seok;Kohyama, Akira
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.2 s.257
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    • pp.205-210
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    • 2007
  • SiC/SiC composites and monolithic SiC materials have been fabricated by the melt infiltration process, through the creation of crystallized SiC phase by the chemical reaction of C and Si. The reinforcing material used in this system was a braided Hi-Nicalon SiC fiber with double interphases of BN and SiC. The microstructures and the mechanical properties of RS-SiC based materials were investigated through means of SEM, TEM, EDS and three point bending test. The matrix morphology of RS-SiS/SiC composites was greatly composed of the SiC phases that the chemical composition of Si and C is different. The TEM analysis showed that the crystallized SiC phases were finely distributed in the matrix region of RS-SiC/SiC composites. RS-SiC/SiC composites also represented a good flexural strength and a high density, accompanying a pseudo failure behavior.

Effect of Si Addition on Resistivity of Porous SiC-Si Composite for Heating Element Application (다공성 SiC-Si 복합체의 전기비저항에 미치는 Si 첨가량의 영향)

  • Jun, Shinhee;Lee, Wonjoo;Kong, Young-Min
    • Korean Journal of Materials Research
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    • v.25 no.5
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    • pp.258-263
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    • 2015
  • To fabricate porous SiC-Si composites for heating element applications, both SiC powders and Si powders were mixed and sintered together. The properties of the sintered SiC-Si body were investigated as a function of SiC particle size and/or Si particle contents from 10 wt% to 40 wt%, respectively. Porous SiC-Si composites were fabricated by Si bonded reaction at a sintering temperature of $1650^{\circ}C$ for 80 min. The microstructure and phase analysis of SiC-Si composites that depend on Si particle contents were characterized using scanning electron microscope and X-ray diffraction. The electrical resistivity of SiC-Si composites was also evaluated using a 4-point probe resistivity method. The electrical resistivity of the sintered SiC-Si body sharply decreased as the amount of Si addition increased. We found that the electrical resistivity of porous SiC-Si composites is closely related to the amount of Si added and at least 20 wt% Si are needed in order to apply the SiCSi composites to the heating element.

Interface formation and thermodynamics between SiC and thin metal films (SiC와 금속박막간의 계면형성 및 열역학)

  • Chang-Sung Lim;Kwang-Bo Shim;Dong-Woo Shin;Keun-Ho Auh
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.6 no.1
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    • pp.62-72
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    • 1996
  • The interface formation and reaction-product morphology between SiC and thin metal films were studied at temperatures between 550 and $1450^{\circ}C$ for various times. The typical reaction layer sequence was CoSi/CoSi+C/CoSi/CoSi+C/ $\cdots$ /SiC reaction at 1050 and $1250^{\circ}C$ for 2 h, while $Ni_2Si/Ni_2Si+C/Ni_2Si/Ni_2Si+C/ {\cdots} /SiC$ at 950 and 105$0^{\circ}C$ for 2 h. Carbon precipitated preferentially on the outer surface and crystallized as graphite above $1450^{\circ}C$ for SiC/Co reaction zone and $1250^{\circ}C$ for SiC/Ni. The mechanism of the periodic band structure formation with carbon precipitation behaviour was discussed in terms of thermodynamic considerations.

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Current Status of $SiC_{f}/SiC$ Composites Material in Fusion Reactor

  • Yoon, Han-Ki;Lee, Sang-Pill
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.166-171
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    • 2007
  • The characterization of monolithic SiC and SiCf/SiC composite materials fabricated by NITE and RS processes was investigated in conjunction with the detailed analysis of their microstructure and density. The NITE-SiC based materials were fabricated, using a SiC powder with average size of 30 nm. RS- SiCf/SiC composites were fabricated with a complex slurry of C and SiC powder. In the RS process, the average size of starting SiC particle and the blending ratio of C/SiC powder were $0.4\;{\mu}m$ and 0.4, respectively. The reinforcing materials for /SiC composites were BN-SiC coated Hi-Nicalon SiC fiber, unidirectional or plain woven Tyranno SA SiC fiber. The characterization of all materials was examined by the means of SEM, EDS and three point bending test. The density of NITE-SiCf/SiC composite increased with increasing the pressure holding time. RS-SiCf/SiC composites represented a great decrease of flexural strength at the temperature of $1000\;^{\circ}C.$

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The effects of brazing conditions on the bond strength of the SiC/SiC and SiC/mild steel joints brazed by Ag-Ti based alloys (Ag-Ti계 합금을 사용한 SiC/SiC 및 SiC/연강 브레이징에서 브레이징 조건이 접합강도에 미치는 영향의 연구)

  • 이형근;이재영
    • Journal of Welding and Joining
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    • v.15 no.5
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    • pp.104-114
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    • 1997
  • The microstructure and bond strength were investigated on the SiC/SiC and SiC/mild steel joints brazed by Ag-5at%Ti alloy. Ag-5at%Ti-2at%Fe and -5at%Fe brazing alloys were also used to see the effects of Fe addition on the bond strength of SiC/SiC brazed joints. Brazing temperature and brazing gap were selected and examined as brazing variables. The microstructure of SiC/SiC brazed joints was affected by Fe addition to the Ag-5at%Ti alloy, but the bond strength was not. Increasing brazing temperature also changed the microstructure of $Ti_5Si_3$ reaction layer and brazing alloy matrix of the SiC/SiC and SiC/mild steel joints, but not the bond strength. Brazing gap had a great effects on the bond strength. Decreasing brazing gap from 0.2 mm to 0.1 mm in SiC/SiC brazing increased the bond strength from 187 MPa to 263 MPa and, in SiC/mild steel brazing, from 189 MPa to 212 MPa. It was concluded that the most important parameter on the bond strength in SiC/SiC and SiC/mild steel brazing was the relative ratio between brazing gap and specimen size.

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Effect of SiC Particle Size on Microstructure of $Si_3N_4/SiC$ Nanocomposites ($Si_3N_4/SiC$ 초미립복합체의 미세조직에 미치는 SiC 입자크기의 영향)

  • 이창주;김득중
    • Journal of the Korean Ceramic Society
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    • v.37 no.2
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    • pp.152-157
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    • 2000
  • Si3N4/SiC nanocomposite ceramics containing 5 wt%dispersed SiC particles were prepared by gas-pressure-sintering at 200$0^{\circ}C$ under nitrogen atmosphere. SiC particles with average sizes of 0.2 and 0.5${\mu}{\textrm}{m}$ were used, and the effect of the SiC particle size on the microstructure was investigated. The addition of SiC particles effectively suppressed the growth of the Si3N4 matrix grains. The effect of grain growth inhibition was higher in the nanocomposites dispersed with fine SiC. SiC particles were dispersed uniformly inside Si3N4 matrix grains and on grain boundaries. When the fine SiC particles were added, large fraction of the SiC particles was trapped inside the grains. On the other hand, when the large SiC particles were added, most of the SiC particles were located on grain boundaries. Typically, the fraction of SiC particles located at grain boundaries was higher in the specimen prepared from $\beta$-Si3N4 than in the specimen prepared from $\alpha$-Si3N4.

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