• Title/Summary/Keyword: 소결 세라믹

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Sintering Behavior and Mechanical Strength of Hydroxyapatite/Polyacrylic Acid Homogeneous Composite (Hydroxyapatite/Polyacrylic Acid 균질복합체의 소결 특성 및 기계적 강도)

  • 이병교;이석기;구광모;이미혜;이형동
    • Journal of the Korean Ceramic Society
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    • v.40 no.6
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    • pp.566-571
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    • 2003

  • Hydroxyapatite (HAp)/Polyacrylic Acid(PAA) homogeneous composites of four different composition ratio were preparation by co-precipitation process with synthetic HAp and PAA as a binder. HAP/PAA composites were molding by cold isostatic pressing and were sintering by various condition in air. Crystallinity and structure of sintered HAp/PAA composites were investigated by XRD and FT-IR. Also, the compressive strength and the fracture surface of sintered specimens were measured by UTM and SEM. HAp/PAA composites were showed phase transformation of partially ${\alpha}$, ${\beta}$-tricalcium phosphate at sintering condition of 1200$^{\circ}C$ and 3 h. The pore size and porosity of sintered body were showed the range of 0.2∼3.0 $\mu\textrm{m}$ and 0.49∼13.43%, respectively. The compressive strength of sintered specimens were appeared the range of 36.6∼58.2 MPa. From these results, the sintered HAp/PAA comosites can be accounted for the microporous HAp having a good compressive strength due to homogeneous pore morphology.

  • https://doi.org/10.4191/KCERS.2003.40.6.566 인용 PDF KSCI

Preparation of β-TCP/TiO2 Composite by Hot-Pressing (가압소결에 의한 β-TCP/TiO2복합체의 제조)

  • 정항철;이종국
    • Journal of the Korean Ceramic Society
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    • v.41 no.3
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    • pp.202-209
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    • 2004

  • Hydroxyapatite(HA)/TiO$_2$ composite powders were prepared by mixing of spherical TiO$_2$ (10-15 nm, 500 nm) and needle-shaped HA (50-70 nm, 120-250 nm) powders which had been synthesized through precipitation, sol-gel and hydrothermal methods. From the three types of starting composite powders (HA/TiO$_2$ wt% of 75/25, 50/50, and 25/75), dense $\beta$-TCP/TiO$_2$ composites were prepared by hot-pressing at 800-100$0^{\circ}C$ for 30 min under the pressure of 30 ㎫ in Af atmosphere. The $\beta$-TCP/TiO$_2$ composites showed different microstructures and sintering densities depending on their powder morphology, composition and sintering temperature. With increasing the sintering temperature and the content of TiO$_2$, sintered density was increased and microstructure became more homogeneous.

  • https://doi.org/10.4191/KCERS.2004.41.3.202 인용 PDF KSCI

Role of CaO in the Sintering of 12Ce-TZP Ceramics (12Ce-TZP 세라믹스의 소결에서의 CaO의 역할)

  • 박정현;문성환;박한수
    • Journal of the Korean Ceramic Society
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    • v.29 no.4
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    • pp.65-65
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    • 1992

  • Role of CaO in the sintering of 12Ce-TZP ceramics was studied. The addition of small amounts of CaO increase the densification rate of 12Ce-TZP by altering lattice defect structure and the diffusion coefficient of the rate controlling species, namely cerium and zirconium cations. CaO also inhibits grain growth during sintering and allows the sintering process to proceed to theoretical density by maintaining a high diffusion flux of vacancies from the pores to the grain boundaries. The inhibition of grain growth is accomplished by the segregation of solute at the grain boundaries, causing a decrease in the grain boundary mobility. The segregation of calcium was revealed by AES study.