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Low‐Temperature Fabrication of Porous β‐SiC Ceramics in Sodium Vapor
Author(s) -
Kawamura Fumihiro,
Yamane Hisanori,
Yamada Takahiro,
Yin Shu,
Sato Tsugio
Publication year - 2008
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.02021.x
Subject(s) - materials science , ceramic , silicon carbide , scanning electron microscope , carbon fibers , carbon black , transmission electron microscopy , amorphous solid , silicon , microstructure , composite material , chemical engineering , analytical chemistry (journal) , mineralogy , nanotechnology , crystallography , metallurgy , composite number , chemistry , natural rubber , chromatography , engineering
β‐silicon carbide (SiC) porous ceramics were synthesized from pelletized powder mixtures of silicon (Si) and fullerene or Si and amorphous carbon (carbon black) at 1000 K for 24 h in sodium (Na) vapor. The relative density of the ceramics was 29%–34% of the theoretical density of SiC. Scanning electron microscopic observation of the fracture surface showed that the ceramics prepared with fullerene were agglomerates of submicrometer‐sized SiC particles and open spaces. The samples prepared with carbon black had a smooth fracture surface with cavities and voids. Using transmission electron microscopy, grains of over 250 nm and a diffuse electron diffraction ring pattern of β‐SiC were observed for the sample prepared with fullerene, and grains of 10–20 nm with a β‐SiC spot ring pattern for the sample prepared with carbon black. A surface area of 11–17 m 2 /g and a mesopore size distribution in the range of 2–10 nm were shown by a nitrogen adsorption technique. Energy‐dispersive X‐ray analysis detected 1–5 at.% of Na against Si on the fracture surface of the ceramics.