• 대한기계학회논문집A
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• 제29권3호
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• pp.425-431
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• 2005

The efficiency of complex slurry preparation route for developing the high performance SiC matrix of $RS-SiC_{f}/SiC$ composites has been investigated. The green bodies for RS-SiC materials prior to the infiltration of molten silicon were prepared with various C/SiC complex slurries, which associated with both the sizes of starting SiC particles and the blending conditions of starting SiC and C particles. The characterization of Rs-SiC materials was examined by means of SEM, EDS and three point bending test. Based on the mechanical property-microstructure correlation, the process optimization is also discussed. The flexural strength of Rs-SiC materials greatly depended on the content of residual Si. The decrease of starting SiC particle size in the C/SiC complex slurry was effective for improving the flexural strength of RS-SiC materials.

• 한국주조공학회지
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• 제10권4호
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• pp.309-315
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• 1990

Aluminum alloy matrix composites reinforced by SiC particles were prepared by rheocompocasting, a process which consists of the incoporation and distribution of reinforcement by stirring within a semi-solid alloy. When the volume fraction of SiCp and stirring speed were fixed, the dispersion of SiCp in Al-matrix alloy depended on stirring time and solid volume fraction in slurry. The results were as follows : 1) As a dispersed SiCp during stirring at $647^{\circ}C$ in 6063-Al alloy, SiC was better dispersed than that other temperature, where solid volume fraction was 43% in slurry. 2) When increased solid fraction in slurry, rate of dispersing SiC increased during stirring and porosities decreased in matrix alloy after casting. 3) Inspite of stirring with 800rpm, since solid particles of matrix alloy in slurry joined each other and occured joining growth, so that SiC was not dispersed into solid particle.

• 한국세라믹학회지
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• 제46권5호
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• pp.447-451
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• 2009

Continuous SiC fiber-reinforced SiC composites ($SiC_f$/SiC) were fabricated by electrophoretic deposition (EPD). Nine types of slurries with different powder contents, binder resin amounts and slurry pH were deposited on Tyranno$^{TM}$-SA fabrics by EPD at 135 V for ten minutes to determine the optimal conditions. Further EPD using the optimum slurry conditions was performed on fabrics with four different pyrolitic carbon (PyC) thicknesses. The density of the hot-pressed composites decreased with increasing PyC thickness due to the difficulty of infiltrating the slurry into the narrow gaps between the fibers. On the other hand, the mechanical strength increased with increasing PyC thickness despite the decrease in density, which was explained by the enhanced crack deflection with increasing PyC thickness. The $SiC_f$/SiC composites showed the highest density and flexural strength of 94% and 342 MPa, respectively, showing EPD as a feasible method for dense $SiC_f$/SiC fabrication.

• 한국생산제조학회지
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• 제23권6호
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• pp.547-554
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• 2014

CVD SiC is a perfect material used for molds/dies in hot press molding of glass lens. In its fabrication process, nano-precision polishing is essential finally. For this purpose, a novel polishing method using MCF (Magnetic Compound Fluid) slurry is proposed. In this method, MCF slurry is supplied into a given gap between the workpiece and a MCF slurry carrier, and constrained within the polishing zone by magnetic forces from permanent magnet. In this paper, after an experimental rig used to actually realize the proposed method has been constructed, the fundamental polishing characteristics of CVD SiC such as the effects of process parameters including MCF slurry composition on work-surface roughness were experimentally investigated. As a result, nano-precision surface finish of CVD SiC was successfully attained with MCF slurry and the optimum process parameters for obtaining the smoothest work-surface were determined.

• 한국세라믹학회지
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• 제44권7호
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• pp.349-353
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• 2007

2D SiC fiber-SiC (SiC/SiC) composites were fabricated via slurry infiltration and a stacking process. The effects of the additive composition and content in SiC slurries and the effect of the sintering time on the sintered density and strength of SiC/SiC composites were investigated. A slurry containing $Al_2O_3-Y_2O_3-MgO$ (AYM) additives led to a higher strength compared to a slurry containing $Al_2O_3-Y_2O_3-CaO$ (AYC) additives. The sintered density increased as the sintering time increased and showed a maximum (>98%) at 4 h. In contrast, the flexural strength increased as the sintering time increased and showed a maximum (615 MPa) at 6 h. The relative density and flexural strength increased as the additive content increased.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.380-385
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• 2004

The efficiency of complex slurry preparation route for developing the high performance SiC matrix of RS-SiCf/SiC composites has been investigated. The green bodies for RS-SiC materials prior to the infiltration of nw/ten silicon were prepared with various C/SiC complex matrix slurries, which associated with both different sizes of starting SiC particles and blending ratios of starting SiC and carbon particles. The characterization of RS-SiC materials was examined by means of SEM, TEM, EDS and three point bending test. Based on the mechanical property-microstructure correlation, process optimization methodology is also discussed. The flexural strength of RS-SiC materials greatly depended on the content of residual Si. The decrease of starting SiC particle size in the C/SiC complex slurry was effective for improving the flexural strength of RS-SiC materials.

• 자원리싸이클링
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• 제26권6호
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• pp.45-49
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• 2017

반도체 산업의 실리콘(Si) 제조과정에서 실리콘과 실리콘 카바이드(SiC)를 포함하는 폐 슬러리가 발생하게 된다. 폐 슬러리는 단순히 시멘트로 고형화하여 보관하거나 매립하는 방법이 있지만, 본 연구에서는 제강공정의 부원료인 승온제로 사용하는 방안이 제시되었다. 폐 슬러리를 정제하여 분말을 만들어 SiC계 슬러지 브리켓으로 재활용하였다. SiC계 슬러지 브리켓은 화학적 성분을 분석하고 투입시기와 투입량에 따른 승온제 특성을 관찰하였다. 이 결과 SiC계 슬러지 브리켓은 제강공장에서 저비용과 고효율로 용강온도를 높이는 효과가 있었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.376-380
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• 2003

The microstructure and the mechanical properties of RS-SiC and RS-$SiC_f/SiC$ materials have been investigated in conjunction with the content of residual silicon and porosity. The mechanical properties of RS-SiC materials suffered from the thermal exposure were also examined. RS-SiC based materials bave been fabricated using the complex matrix slurry with different composition ratios of SiC and C panicles. The characterization of RS-SiC based materials was investigated by means of SEM, EDS ~d three point bending test. Based on the mechanical property-microstructure correlation, the high temperature applicability of RS-SiC based materials was discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.361-362
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• 2008

• 한국세라믹학회지
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• 제45권4호
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• pp.204-207
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• 2008

This paper presents a new process for producing SiC fiber-SiC matrix(SiC/SiC) composites by reaction sintering. The processing strategy for the fabrication of the SiC/SiC composites involves the following: (1) infiltration of the SiC fiber fabric using a slurry consisting of Si and C precursors, (2) stacking the slurry-infiltrated SiC fiber fabric at room temperature, (3) cross-linking the stacked composites, (4) pyrolysis of the stacked composites, and (5) hot-pressing of the pyrolyzed composites. It was possible to obtain dense SiC/SiC composites with relative densities of >96% and a typical flexural strength of ${\sim}400$ MPa.