• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.159-160
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• 2003

금속과 유사한 전도성을 가진 공액이중결합의 전기전도성 고분자를 사용한 Langmuir-Blodett (LB) 막의 제조에 관한 연구는 그 범위가 넓으며, 지금까지 많은 연구 논문들이 보고되고 있다[1]. 특히 전도성이 뛰어난 polyaniline, polypyrrole, polythiophene은 전도성과 stability가 우수하여 전기 전도성 LB 막에 대한 연구들이 많이 진행되어 왔다[2]. 본 연구에서는 이와 같은 전기전도성 유기물질을 사용한 전도성 LB막이 수직방향에 비해 수평방향의 전기전도도가 크다는 전기적 장점을 이용하여 전도성 LB막을 제조하기 위해 새로운 전도성 고분자를 합성하여 전기 전도성을 띄는 LB 막을 제조하였다[3,4]. (중략)

• 한국재료학회지
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• 제9권6호
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• pp.577-582
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• 1999

전도성 $Si_3N_4$-TiN 세라믹 복합재료를 제조하기 위해 성형체를 $1450^{\circ}C$에서 20시간 질화처리한 후 $1950^{\circ}C$에서 3.5시간 가스압소결 기술에 의해 후소결하였다. 초기 분말로 약 $10\mu\textrm{m}$로 된 상용 Si분말, 100mesh와 325mesh로된 Ti분말, 그리고 미세한 $\2.5mu\textrm{m}$ TiN분말을 사용하였다. Ti분말울 사용한 $Si_3N_4$-TiN 소결체에서 상대밀도 및 파괴인성값은 다량의 조대한 기공의 존재로 인하여 낮은 값을 보였다. 그러나 TiN분말을 사용한 $Si_3N_4$-TiN 복합체에서 파괴인성, 파괴강도 및 전기저항은 각각 $5.0MPa{\cdot}m^{1/2}$, 624MPa 그리고 $1400{\omega}cm$였다. 복합체에서 TiN 업자의 분산은 $Si_3N_4$ 업자의 조대한 봉상형태로의 성장올 방해하며 $Si_3N_4$/TiN 계면에 강한 변형장울 만든다. $Si_3N_4$-TiN 복합체의 전기전도도 및 기계적 특성을 향상시키기 위해 TiN 업자가 균일하게 분산 된 미세조직 제어가 요망된다.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.1275-1278
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• 2012

도전성 복합체의 최적 설계 요소와 세라믹 제조기법을 찾고 발열체 제작을 위한 기초기반 기술을 확보하였다. 제품 응용시 세라믹 발열체를 하나의 몸체로 제작하여 접촉 저항을 최대한 줄이면 시스 발열체보다 1.1배 느린 초기 상승 온도 속도를 높일 수 있고, 보온력에서는 SiC계 세라믹 발열체가 시스 발열체보다 약 2.7배 높기 때문에 제품의 사용 기간이 길어질수록 에너지 절감 효과를 얻을 수 있어, 경제성 면에서 대단히 유리하게 평가 된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.853-855
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• 1998

The electrical resistivity and mechanical properties of the hot-pressed and annealed ${\beta}$-SiC+39vol.%$ZrB_2$ electroconductive ceramic composites were investigated as a function of the liquid forming additives of $Al_{2}O_{3}+Y_{2}O_{3}$(6:4wt%). In this microstructures. no reactions were observed between $\beta$-SiC and $ZrB_2$, and the relative density is over 97.6% of the theoretical density. Phase analysis of composites by XRD revealed mostly of a $\alpha$-SiC(6H, 4H), $ZrB_2$ and weakly $\beta$-SiC(15R) phase. The fracture toughness decreased with increased $Al_{2}O_{3}+Y_{2}O_{3}$ contents and showed the highest for composite added with 4wt% $Al_{2}O_{3}+Y_{2}O_{3}$ additives. The electrical resistivity increased with increased $Al_{2}O_{3}+Y_{2}O_{3}$ contents because of the increasing tendency of pore formation according to amount of liquid forming additives $Al_{2}O_{3}+Y_{2}O_{3}$. The electrical resistivity of composites is all positive temperature coefficient resistance(PTCR) against temperature up to $700^{\circ}C$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1436-1438
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• 2001

The $\beta$-SiC + $ZrB_2$ ceramic electroconductive composites were pressureless-sintered and annealed by adding 12wt% $Al_2O_3$ + $Y_2O_3$ (6 : 4wt%) powder as a function of sintering temperature. The relative density showed the highest value of 81.1% at 1900$^{\circ}C$ sintering temperature. The phase analysis of the composites by XRD revealed of $\alpha$-SiC(6H), $TiB_2$, $Al_5Y_2O_{12}$ and $\beta$-SiC(15R). Flexural strength showed the highest value of 230 MPa for composites sintered at 1900$^{\circ}C$. The vicker's hardness and the fracture toughness showed the highest value of increased with increasing sintering temperature and showed the highest of 9.88 GPa and 6.05 $MPa{\cdot}m^{1/2}$ at 1900$^{\circ}C$. The electrical resistivity was measured by the Pauw method from 25$^{\circ}C$ to 700$^{\circ}C$. The electrical resistivity of the composites showed the PTCR (Positive Temperature Coefficient Resistivity).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.311-313
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• 1997

The effects of porosity on the pressureless sintered $\beta$-SiC-$ZrB_2$ composites with $Al_2O_3$ additions(4, 8, 12wt.%) under argon atmosphere were investigated. Relative density of $\beta$-SiC-$ZrB_2$ composites were decreased with the $Al_2O_3$ content. The relative density and fracture toughness of $\beta$-SiC-$ZrB_2$ with 4wt% $Al_2O_3$ are 93.2%, $1.323MPa{\cdot}m^{1/2}$ respectively. The Vicker's hardness and flexural strength of $\beta$-SiC-$ZrB_2$ with 12wt.% $Al_2O_3$ are 0.492GPa, 261MPa respectively. Fracture toughness of $\beta$-SiC-$ZrB_2$ composites are directly proportional to relative density.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.242-242
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• 2004

The composites were fabricated 61 vol.%α-α-SiC and 39vol.% WC powders with the liquid forming additives of 12wt% Al₂O₃＋Y₂O₃ by pressureless annealing at 1700, 1800, 1900℃ for 4 hours. The result of phase analysis of composites by XRD revealed α-SiC(2H), WC, and YAG($Al_5Y_3O_{12}$) crystal phase. The relative density, the flexural strength, fracture toughness and Young′s modulus showed respectively the highest value of 99.4%, 375.76㎫, 5.79㎫ㆍ$m^{\frac{1}{2}}$, and 106.43㎬ for composite by pressureless annealing temperature 1900℃ at room temperature. The electrical resistivity showed the lowest value of 1.47×$10^{-3}$/Ω·㎝ for composite by pressureless annealing temperature 1900℃ at 25℃. The electrical resistivity of the α-SiC-WC composites was all positive temperature cofficient resistance (PTCR) in the temperature ranges from 25℃ to 500℃.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.241-247
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• 2004

The composites were fabricated 61 vol.%$\alpha$-$\alpha$-SiC and 39vol.% WC powders with the liquid forming additives of 12wt% $Al_2$O$_3$＋Y$_2$O$_3$ by pressureless annealing at 1700, 1800, 190$0^{\circ}C$ for 4 hours. The result of phase analysis of composites by XRD revealed $\alpha$-SiC(2H), WC, and YAG(Al$_{5}$ Y$_3$O$_{12}$ ) crystal phase. The relative density, the flexural strength, fracture toughness and Young's modulus showed respectively the highest value of 99.4%, 375.76㎫, 5.79㎫ㆍm$\frac{1}{2}$, and 106.43㎬ for composite by pressureless annealing temperature 190$0^{\circ}C$ at room temperature. The electrical resistivity showed the lowest value of 1.47${\times}$10$^{-3}$ $\Omega$$.$cm for composite by pressureless annealing temperature 190$0^{\circ}C$ at $25^{\circ}C$. The electrical resistivity of the $\alpha$-SiC-WC composites was all positive temperature cofficient resistance (PTCR) in the temperature ranges from $25^{\circ}C$ to 50$0^{\circ}C$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1289-1290
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• 2007

The composites were fabricated 61Vo.% ${\beta}$-SiC and 39Vol.% $TiB_2$ powders with the liquid forming additives of 12wt% $Al_{2}O_{3}+Y_{2}O_{3}$ as a sintering aid by pressure or pressureless annealing at $1650^{\circ}C$ for 4 hours. The present study investigated the influence of annealed sintering on the microstructure and mechanical of SiC-$TiB_2$ electroconductmive ceramic composites. Reactions between SiC and transition metal $TiB_2$ were not observed in the microstructure and the phase analysis of the SiC-$TiB_2$ electroconductive ceramic composites. Phase analysis of SiC-$TiB_2$ composites by XRD revealed mostly of ${\alpha}$-SiC(6H), $TiB_2$, and In Situ YAG($Al_{5}Y_{3}O_{12}$). The relative density, the flexural strength, the Young's modulus showed the highest value of 86.69[%], 136.43[MPa], 52.82[GPa] for pressure annealed SiC-$TiB_2$ ceramic composites.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.92-97
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• 1999

The mechanical and electrical properties of the hot-pressed and annealed $\beta-Sic$+39vol.%$ZrB_2$ electroconductive ceramic composites were investigated as a function of the liquid forming additives of $Al_2O_3+Y_2O_3(6:4wt%)$. In this microstructures, no reactions and elongated $\alpha$-SiC grains with equiaxed $ZrB_2$, gains were observed between $\beta-SiC$ and $ZrB_2$, and the relative density was over 97.6% of the theoretical density. Phase analysis of the composites by XRD revealedmostly of $\alpha$-SiC(6H, 4H), $ZrB_2$, and weakly $\beta-SiC$(15R) phase. The fracture toughness decreased with increasing $Al_2O_3+Y_2O_3$ contents and showed the highest of $6.37MPa.m^{\fraction ane-half}$ for composite added with 4wt% $Al_2O_3+Y_2O_3$ additives at room temperature. The electrical resistivity increased with increasing $Al_2O_3+Y_2O_3$contents and showed the lowest of $1.51\times10^{-4}\Omega.cm$ for composite added with $Al_2O_3+Y_2O_3$ additives at $25^{\circ}C$. This reason is the increasing tendency of pore formation according to amount of liquid forming additives $Al_2O_3+Y_2O_3$. The electrical resistivity of the composites was all positive temperature coefficient resistance(PTCR) against temperature up to $700^{\circ}C$.