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Novel SiC synthesis method applicable to SiC solid phase sintering
Author(s) -
Usukawa Ryutaro,
Ishikawa Toshihiro
Publication year - 2019
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13320
Subject(s) - materials science , carbothermic reaction , sintering , carbonization , stoichiometry , chemical engineering , aqueous solution , curing (chemistry) , ball mill , composite material , carbide , scanning electron microscope , organic chemistry , chemistry , engineering
Most of the present production processes of SiC sintered bodies require some powder mixing using a mechanical milling process (ball milling, and so on). In this case, relatively long hours are required, and there is the problem of contamination during the preparation process. To avoid these problems, we developed a new process for obtaining a self‐sinterable, stoichiometric SiC powder, whose precursor material is water‐soluble; the precursor material was synthesized from aqueous silica and citric acid containing a small amount of aluminum compound. In order to obtain the stoichiometric SiC composition, the above aqueous precursor material was adequately cured in air (200°C‐400°C); subsequently carbonization reaction (~800°C) in nitrogen atmosphere, carbothermal reduction (~1600°C) in argon atmosphere, and pressureless sintering (~1900°C) were performed. Among these processes, the curing process (cross‐linking process) is very important for obtaining the equivalent composition (silica and carbon) for the subsequent carbothermal reduction. In this study, the adequate curing temperature and suitable preparation condition for the carbothermal reduction were investigated for the production of stoichiometric self‐sinterable SiC powder. The pressureless sintered body achieved using the obtained SiC powder demonstrated a desirable trans‐crystalline fracture behavior.