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반응소결 탄화규소 세라믹스의 열물성과 기계적 특성에 미치는 SiC 크기의 영향
권창섭,오윤석,이성민,한윤수,신현익,김영석,김성원,Kwon, Chang-Sup,Oh, Yoon-Suk,Lee, Sung-Min,Han, Yoonsoo,Shin, Hyun-Ick,Kim, Youngseok,Kim, Seongwon 한국분말야금학회 2014 한국분말재료학회지 (KPMI) Vol.21 No.6
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.
Fabrication and properties of reaction-bonded SiC prepared by gelcasting
Lifang Nie,Hongyu Gong,Tao Zhang,Yujun Zhang 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.1
The properties of green and reaction-bonded SiC (RBSC) samples prepared by a gelcasting technique are investigated in this paper. The results show that solid loading and monomer content of the suspension in the gelcasting process are the main factors that effect the density and shrinkage of the green bodies. A slurry with a solid loading of 58 vol% was solidified in situ to a green body with a linear shrinkage of 1.1% and flexural strength of 27 ± 2 MPa. SEM micrographs show that the SiC and C particles in the green body were closely compact by a connection of the polymer network. The maximum density and flexural strength of samples reaction sintered at 1700℃ in vacuum were 2.97 g/㎤ and 378 ± 12 MPa respectively. The properties of green and reaction-bonded SiC (RBSC) samples prepared by a gelcasting technique are investigated in this paper. The results show that solid loading and monomer content of the suspension in the gelcasting process are the main factors that effect the density and shrinkage of the green bodies. A slurry with a solid loading of 58 vol% was solidified in situ to a green body with a linear shrinkage of 1.1% and flexural strength of 27 ± 2 MPa. SEM micrographs show that the SiC and C particles in the green body were closely compact by a connection of the polymer network. The maximum density and flexural strength of samples reaction sintered at 1700℃ in vacuum were 2.97 g/㎤ and 378 ± 12 MPa respectively.
반응소결 탄화규소의 접동조건에 따른 마찰계수 및 미세구조
김호균,김인섭,이병하 한국세라믹학회 1995 한국세라믹학회지 Vol.32 No.7
Reaction-bonded SiC-Si material was fabricated by infiltration of Si melt into a mixture of $\alpha$-SiC and carbon at 175$0^{\circ}C$ under the vacuum atmosphere. Wear properties were analyzed by ball-on-plate wear tester, changing loading weight, sliding speed, sliding time and atmosphere, Results showed that the friction coefficient was decreased with increasing load and sliding velocity. The lowest friction coefficient of 0.05 was obtained under an oil atmosphere. The analysis of the wear surface indicated that the areas wehre particles were pulled out and where free silicon particles worn out preferentially serve as liquid reservoirs to decrease the wear resistance.
원자력 극한환경용 세라믹 열교환기 소재로서 반응소결 SiC 세라믹스 제작성
정충환,박지연,Jung, Choong-Hwan,Park, Ji-Yeon 한국세라믹학회 2011 한국세라믹학회지 Vol.48 No.1
Silicon carbide (SiC) is a candidate material for heat exchangers for VHTR (Very High Temperature Gas Cooled Reactor) due to its refractory nature and high thermal conductivity. This research has focused on demonstration of physical properties and mock-up fabrication for the future heat exchange applications. It was found that the SiC-based components can be applied for process heat exchanger (PHE) and intermediate heat exchanger (IHX), which are operated at $400{\sim}1000^{\circ}C$, based on our examination for the following aspects: optimum fabrication technologies (design, machining and bonding) for compact design, thermal conductivity, corrosion resistance in sulfuric acid environment at high temperature, and simulation results on heat transferring and thermal stress distribution of heat exchanger mock-up.
용융 Si-C-SiC계에서 $\beta$-SiC 생성기구
서기식,박상환,송휴섭 한국세라믹학회 1999 한국세라믹학회지 Vol.36 No.6
${\beta}$-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.
다층 기공구조를 갖는 다공성 반응소결 탄화규소 다공체 제조
조경선,김규미,박상환,Cho, Gyoung-Sun,Kim, Gyu-Mi,Park, Sang-Whan 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.5
Reaction Bonded Silicon Carbide(RBSC) has been used for engineering ceramics due to low-temperature fabrication and near-net shape products with excellent structural properties such as thermal shock resistance, corrosion resistance and mechanical strength. Recently, attempts have been made to develop hot gas filter with gradient pore structure by RBSC to overcome weakness of commercial clay-bonded SiC filter such as low fracture toughness and low reliability. In this study a fabrication process of porous RBSC with multi-layer pore structure with gradient pore size was developed. The support layer of the RBSC with multi-layer pore structure was fabricated by conventional Si infiltration process. The intermediate and filter layers consisted of phenolic resin and fine SiC powder were prepared by dip-coating of the support RBSC in slurry of SiC and phenol resin. The temperature of $1550^{\circ}C$ to make Si left in RBSC support layer infiltrate into dip-coated layer to produce SiC by reacting with pyro-carbon from phenol resin.
SiC Fiber 강화 다공질 반응 소결 탄화규소 Composite의 제조 및 기계적 특성
한재호,박상환,Han, Jae-Ho,Park, Sang-Whan 한국세라믹학회 2006 한국세라믹학회지 Vol.43 No.8
In this study, chopped Hi-Nicalon SiC fiber Reinforced Porous Reaction Bonded SiC (RBSC) composites and it fabrication process were developed by using Si melt infiltration process. The porosity and average pore size in fabricated chopped SiC fiber reinforced porous RBSC composites were in the range of $30{\sim}40%$ and $40-90{\mu}m$, which mainly determined by the SiC powder size used as starting material and amount of residual Si in porous composites. The maximum flexural strength of chopped SiC fiber reinforced porous RBSC composite was as high as 80 MPa. The delayed fracture behavior was observed in chopped SiC fiber reinforced porous RBSC composites upon 3-point bending strength test.
Praveen Wilson,Sujith Vijayan,K. Prabhakaran 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-
Microcellular SiC foams (MSiCFs) are produced by thermal setting of dispersions of silicon and NaClpowders in molten sucrose-glycerol solutions in a mould followed by carbonization, NaCl removal andreaction bonding at 1500 C. The acidic silica layer on silicon particle surface catalyses the setting of thepastes byOH condensation. The SiC nanowires grown in situ by a catalyst-free vapour–solid (VS)mechanism creates web-like architecture within the microcells (cell size2 to 22 mm) of the foams. TheMSiCFs with porosity in the range of 86.8–91.1 vol.% exhibit thermal conductivity and compressivestrength in the ranges of 0.334–0.758 W m 1 K 1 and 0.97–2.38 MPa, respectively. The MSiCFs showexcellent electromagnetic interference (EMI) shielding property in the X-band frequency regionenhanced by the in situ grown SiC nanowires within microcells. The EMI shielding effectiveness (45.6 dB)and specific shielding effectiveness (137 dB g-1 cm3) are the highest reported for SiC foams.