Study on the fabrication of Ceramic Core using a Gel-casting Process in Aqueous Medium(II) : Physical Properties of Sintered Ceramic Core Body

수용액 매체에서 젤-케스팅 공정을 이용한 세라믹 코어 제조에 관한 연구(II) : 세라믹 코어 소결체의 물성

  • Kim, Jae-Won (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials) ;
  • Kim, Du-Hyeon (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials) ;
  • Kim, In-Su (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials) ;
  • Yu, Yeong-Su (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials) ;
  • Choe, Baek-Gyu (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials) ;
  • Kim, Ui-Hwan ;
  • Jo, Chang-Yong (Materials Processing Deplrtment, Koreo Institute ofMachinerrand Materials)
  • 김재원 (한국기계연구원 내열재료그룹) ;
  • 김두현 (한국기계연구원 내열재료그룹) ;
  • 김인수 (한국기계연구원 내열재료그룹) ;
  • 유영수 (한국기계연구원 내열재료그룹) ;
  • 최백규 (한국기계연구원 내열재료그룹) ;
  • 김의환 (한전전력연구원 발전연구실) ;
  • 조창용 (한국기계연구원 내열재료그룹)
  • Published : 2001.06.01

Abstract

The effect of sintering condition on the mechanical properties and leachability of polydispersed ceramic core body made by gel-casting process in aqueous medium have been investigated. The polydispersed ceramic slip that has low viscosity($\leq$1000cP, at 1000cP (at $50sec^{-1}$ ) and high solid loading(50vo1%) was obtained. The green bodies were fabricated through casting and gelation at room temperature followed by drying at $25^{\circ}C$for 48hrs under relative humidity of 80%. Crack-free green body was successfully fabricated through the above process. The strength at room temperature, apparent bulk density, and shrinkage of the ceramic core body increased propotionally with increasing sintering temperature(1100~150$0^{\circ}C$). However, porosity of the ceramic core body showed relatively low vague. Leaching rate of sintered core body increased with increasing porosity of the sintered body, and was significantly dependent upon the concentration of alkali caustic solution at the same leaching temperature.

수용성 매체에서 젤-케스팅 공정을 이용하여 용융실리카를 기본으로 하는 다성분계 세라믹 코어 (中子)를 제조하고, 소결조건에 따른 제반 기계적 물성과 알칼리 부식용액에 의한 용출특성을 고찰하였다. 1000cP (at $50sec^{-1}$ ) 이하의 낮은 점도를 갖는 50vol%의 고농도 다성분계 세라믹 슬림의 제조가 가능하였다. 성형체는 안정화시킨 슬림을 몰드에 부어 상온에서 겔화시킨 후 $25^{\circ}C$, 80% 상대습도 분위기 하에서 48시간동안 건조시켜 제조하였으며 건조된 성형체에는 균열이 발생하지 않았다. 세라믹 코어 성형체의 소결온도가 상승할 수록 상온강도, 겉보기 밀도, 수축률은 시편의 기공도와 역비례하여 증가하였다. 세라믹 코어 소결체의 용출속도는 동일한 온도에서 알칼리 부식용액의 농도에 의존하였으며, 소결체의 기공도가 클수록 증가하였다.

Keywords

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