Issue
HWAHAK KONGHAK,
Vol.35, No.6, 908-914, 1997
Sol-Gel법에 의한 Mullite Fiber의 제조 및 미세구조의 변화
Preparation of Mullite Fiber by Sol-Gel Method and Microstructure of Sintered Fiber
본 연구에서는 고순도 알콕사이드를 출발 물질로하여 졸-겔법으로 mullite 섬유를 제조하고자 하였다. 졸-겔법의 다양한 제법 중 중합 경로를 이용하는 방법이 mullite로의 결정화 온도가 가장 낮고 방사 가능한 점도가 가장 길게 유지되므로 이를 선택하여 mullite 섬유를 제조하였다. Mullite 겔 섬유의 제조시 요구되는 몰비를 조정하고 졸의 유변학적 거동에 따른 섬유 방사능의 고찰 및 소성 온도 변화에 따른 mullite 섬유의 결정화도 및 이에 따른 미세구조의 변화를 살펴보고자 하였다. 이의 결과로 연속적인 섬유의 방사가 가능한 점도는 상대시간 0.97에서 약 104cP로 나타났으며 1,300℃ 이상에서 소성 온도 및 시간이 증가할수록 결정화도가 커지며 1,500℃로 3시간 동안 소성하여 섬유의 내부까지 결정화된 mullite 섬유를 얻을 수 있었다.
In this study, the mullite gel fiber was prepared from high purity metal alkoxides. The rheological properties of mullite sol prepared from sol-gel method have been investigated as a function of gelation temperature. The mullite gel had good spinnability ranging 12,000-13,000cP. The mullite gel fiber was calcined and sintered from high temperature muffle furnace. Then mullite fiber was analyzed by FT-IR, XRD, EPMA and SEM. From these analyses, Al-O-Si chemical bond might result in the homogeneous mullite composition. And mullite crystalline phase was obtained over 1,300℃ of sintering temperature. It was shown that atomic ratio (Al:Si) of prepared mullite fiber was 3:1. The microstructure of mullite fiber was investigated at the various temperature. It was observed that calcined fiber had complete mullite phase and mullite fiber which was calcined and sintered at 1,500℃ for 3 hr had completely grown mullite crystal.
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