Effects of Coating Conditions on the Thickness and Morphology of Alumina- or Carbon-Coated Layers on SiC Whiskers

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J. Korean Ceram. Soc. > Volume 36(5); 1999 > Article

Journal of the Korean Ceramic Society 1999;36(5): 513.

알루미나 또는 카본 코팅 SiC 휘스커의 코팅층 두께 및 형상에 미치는 코팅조건의 영향

배인경, 장병국¹, 조원승, 최상욱

인하대학교 무기재료공학과
¹한국에너지 기술연구소

Effects of Coating Conditions on the Thickness and Morphology of Alumina- or Carbon-Coated Layers on SiC Whiskers

ABSTRACT

Alumina-coated SiC whiskers wee prepared by the calcination (1150$^{circ}C$, 1h, Ar) of the alumina hydrate layer which was precipitated homogeneously on whisker surface from a solution of Al2(SO4)3 and urea as a precipitant. In addition carbon coated SiC whiskers were prepared by the pyrolysis (1000$^{circ}C$, 4h Ar) of phenolic resin coated whisker. The effects of coating conditions on the thickness and morphology of the coated layers were examined by SEM and TEM. It was found that Al2O3-coating layers become thinner and more uniform with decreasing the Al2(SO4)3 concentration. Thin (0.075-0.1$mutextrm{m}$) and uniformly alumina-coating layers were obtained at the Al2(SO4)3 concentration 0.010mol/l. On the other han carbon-coating layers were uniform but very thin (5-16 nm) in thickness. For thicker carbon-coating layers ethanol as a disperse medium was found to be more efficient compared tousing acetone.

Key words: SiC whisker, Alumina coating, Cabon coating, Homogeneous precipitation method, Pyrolysis of Phenolic