화학공학소재연구정보센터
Journal of the Korean Industrial and Engineering Chemistry, Vol.16, No.5, 648-652, October, 2005
초미세 분쇄 분말로 제조된 K+-beta-aluminas의 치밀화 연구
Densification Study of K+-beta-aluminas Prepared from Their Ultra-fine Milled Powder
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초록
대기압하에서 소결이 어렵다고 알려진 초이온 전도체인 K+-beta-aluminas를 attrition mill을 이용하여 약 350 nm의 평균 입도를 가지는 분말로 분쇄한 후, 시편을 일축가압 성형하여 상압 하에서 동일조성의 분위기 분말을 이용하여 소결하였다. 소결온도는 1400 ℃~1650 ℃까지 50 ℃ 간격으로 소결하였으며, 각 소결온도에서 시간에 따른 소결특성을 살펴보았다. 또한 고온에서 입자 성장 속도를 조절하기 위하여 1600 ℃에서 zone sintering을 실시하였다. 1600 ℃와 1650 ℃에서 소결한 경우와 1600 ℃에서 zone sintering한 시편의 경우, 각각 약 93%와 95%의 소결 밀도를 나타내었다. 1600 ℃ 이상의 온도에서 2 h 이상 장시간 소결할 경우, 입자의 거대성장으로 인하여 소결밀도가 90% 미만으로 감소하였다.
A super ionic conductor, K+-beta-aluminas, which is known to be difficult to obtain in the form of dense sintered density under atmospheric pressure, was pulverized to 350 nm mean particle size using attrition mill. The sample were pressed into tablet form by uniaxial pressing. The specimen was sintered under atmospheric pressure in powder form. Sintering temperature range was 1400 ℃ to 1650 ℃ at 50 ℃ intervals. Additionally, zone sintering was carried out to control the growth grain at high temperature (1600 ℃). The density of specimens that were sintered at 1600 ℃ and 1650 ℃, and sintered at 1600 ℃ by zone sintering were about 93% and 95%, respectively. In the case of the lengthened sintering time to 2 h, the density of specimen was reduced to lower than 90%, since the particles were grown to the duplex microstructure.
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