高純度非晶質窒化ケイ素繊維の結晶化挙動

概要

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The crystallization of high purity polymer derived amorphous Si3N4 fiber was investigated. The amor phous Si_3N_4 fiber was heat treated (1400, 1425, 1450, 1475 and 1500℃, for 1-100h in N_2) , and the crystallini ty was estimated from X ray diffraction patterns. Hex agonal crystalline particles growing on the surface of the fiber were observed by SEM. The crystallization seems to proceed by the vapor phase growth mechan ism, in which SiO vapor takes part as silicon carrier be tween amorphous fiber and crystalline particles. While BN powder was used as a powder bed, the crystalliza tion and grain growth were retarded and crystalline particles were grown inside the fiber. In this case the crystallization seems to proceed by the solid phase growth mechanism. The activation energies were calcu lated for heat treatment with and without BN powder and found to be about 1273 and 602 kJ/mol, respective ly. Durability of Si_3N_4 fiber at 1300 and 1400℃ was estimated.
社団法人日本セラミックス協会の論文
1994-05-01