Densification of mullite precurssor powders isostatically pressed of ultra-high pressure

Conference · Fri Sep 01 04:00:00 EDT 1995

OSTI ID:99175

Kamiya, Hidehiro; Horio, Masayuki ^[1]; Suzuki, Hisao ^[2]

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1. Tokyo Univ. of Agriculture and Technology (Japan)
2. Shizuoka Univ. (Japan); and others

Ultrafine mullite precursor powders were prepared by the heterocoagulation of ultrafine {gamma}-Al{sub 2}O{sub 3} and alkoxide-derived SiO{sub 2} powder. The precursor powder was cold isostatical pressed up to 1 GPa to attain the close packing structure in the green compact. The maximum density of the green compact reached 60 % by collapsing the inter-aggregate pores to reduce the pore size below 10nm. Low-temperature sintering of the heterogeneously aggregated precursor compact could be attained below liquid formation temperature of a mullite with a aid of ultra-high pressure isostatic press. The density of the mullite ceramic reached more than 95 % of theoretical at 1450{degrees}C. Low temperature sintering led to the fine microstructure of the resultant mullite ceramic with an average grain size less than 1 00 nm (nano-structure ceramic).

• OSTI ID: 99175
• Report Number(s): CONF-940911--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKOXIDES
ALUMINIUM OXIDES
CHEMICAL COMPOSITION
GRAIN DENSITY
GRAIN SIZE
MULLITE
PHASE STUDIES
POWDERS
PROCESSING
SINTERING