Microstructural characterization of alumina and silicon carbide slip-cast cakes

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb09010.x· OSTI ID:413305

Smith, P A ^[1]; Kerch, H M ^[2]; Haerle, A G ^[3]; Keller, J ^[4]

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1. Pacific Northwest National Lab., Richland, WA (United States). Materials Sciences Dept.
2. Dept. of Energy, Germantown, MD (United States). Office of Basic Energy Sciences
3. Dow Chemical Co., Midland, MI (United States)
4. Rutgers Univ., Piscataway, NJ (United States). Dept. of Ceramics

The effect of solids loading, particle-size distribution, and suspension viscosity on the resultant microstructure of slip-cast monolithic ceramics prepared from aqueous suspensions of alumina and silicon carbide was studied. Unimodal alumina suspensions (average particle size = 0.6 {micro}m) were prepared at 35, 37, and 42 vol%. Silicon carbide suspensions (average particle size = 0.7 {micro}m) were produced with different quantities of dispersant at 37 vol%. Similarly, aqueous alumina suspensions of 42 and 50 vol% were produced with a bimodal particle-size distribution. The slip-cast microstructures were characterized by mercury porosimetry and small-angle neutron scattering, which provided pore size (distribution), pore fraction, and pore morphology. Essentially, the combination of these techniques deciphered packing differences obtained in the cake microstructures. for the alumina cakes produced from the 35, 37, and 42 vol% suspensions, the individual characterization techniques, mercury intrusion, and the neutron scattering measurements showed that the cake microstructures were similar in pore size and quantity. However, comparison of the techniques and their assumptions showed differences in the pore shape. Mercury porosimetry and neutron scattering showed bimodal porosity for the cake produced form a mixture of 85% 6-{micro}m particles and 15% 0.6-{micro}m particles. Pore volume fraction and pore size increases were correlated with increased viscosity in the silicon carbide suspensions. In addition, the silicon carbide cake microstructures were measured, and homogeneity was evaluated as a function of position in the cast.

• Sponsoring Organization: USDOE
• OSTI ID: 413305
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 10 Vol. 79; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CORRELATIONS
MERCURY
MICROSTRUCTURE
NEUTRONS
PARTICLE SIZE
PARTICULATES
PORE STRUCTURE
POROSIMETERS
POROSITY
SILICON CARBIDES
SLIP CASTING
SLURRIES
SMALL ANGLE SCATTERING
VISCOSITY