Synthesis of monodisperse spherical Si{sub 3}N{sub 4}/SiC composite powder from alkoxides by sol-gel process and heat-treatment

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:530679

Choi, Jae Young; Kim, Chong Hee; Kim, Do Kyung ^[1]

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1. Korea Advanced Institute of Science and Technology (KAIST), Taejon (Korea, Republic of)

Synthesis and structure of monodisperse, spherical Si{sub 3}N{sub 4}/SiC composite powder have been studied. Si{sub 3}N{sub 4}/SiC composite powder was prepared by the heat-treatment of spherical organo-silica, powder. The organo-silica powder was prepared by the hydrolysis of the mixture of phenyltrimethoxysilane(PTMS) and tetraethylorthosilicate(TEOS) in methanol solution of water and ammonia. The organo-silica powder became Si{sub 3}N{sub 4} powder containing carbon by heat-treating at 1500{degrees}C for 8 h under nitrogen. And then Si{sub 3}N{sub 4}/SiC composite powder was obtained by the heat-treatment of the Si{sub 3}N{sub 4} powder in an argon atmosphere. The composition of the Si{sub 3}N{sub 4}/SiC composite powder was changed with the duration of heat-treatment. The Si{sub 3}N{sub 4} powder became Si{sub 3}N{sub 4}/SiC composite powder at 1450{degrees}C for 1 h under argon and finally SiC powder at 1450{degrees}C for 8 h under argon. All the heat-treated powders retained their spherical shape and monodispersity in size. The results of TEM, SEM, and selected area electron diffraction showed that the Si{sub 3}N{sub 4}/SiC composite particle was composed of homogenously mixed nano-sized Si{sub 3}N{sub 4} and SiC particulates.

• OSTI ID: 530679
• Report Number(s): CONF-9604124--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HEAT TREATMENTS
POWDERS
SILICON CARBIDES
SILICON NITRIDES
SOL-GEL PROCESS
SYNTHESIS