Silicon carbide particle size effects in alumina-based nanocomposites

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Acta Materialia

DOI:https://doi.org/10.1016/1359-6454(96)00074-2· OSTI ID:415439

Carroll, L; Sternitzke, M; Derby, B ^[1]

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1. Univ. of Oxford (United Kingdom). Dept. of Materials

Al{sub 2}O{sub 3}/SiC nanocomposites with a systematic variation in their SiC particle size together with monolithic alumina were produced using conventional powder processing, polymer pyrolysis and hot-pressing. The microstructures of the materials were investigated by means of transmission and scanning electron microscopy and correlated to their mechanical properties. All nanocomposites showed a clear increase in strength over similar grain size alumina but no clear dependence on the size of the SiC nano-reinforcement. However, the fracture toughness of the nanocomposites seems to increase with the SiC particle size but with values little changed from the toughness of monolithic alumina as measured by the Vickers indentation technique. The surface and bulk flaw populations were characterized using a Hertzian indentation technique and a Griffith flaw size analysis of strength data. The investigations revealed a significant difference between the monolithic alumina and nanocomposites. The strength increase in the nanocomposites is explained by the observed decrease in both the surface and processing flaw sizes, which further decreased with decreasing SiC particle size.

• OSTI ID: 415439
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 11 Vol. 44; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
COMPOSITE MATERIALS
CORRELATIONS
DEFECTS
FRACTURE PROPERTIES
GRAIN SIZE
HOT PRESSING
MECHANICAL PROPERTIES
MICROSTRUCTURE
POLYMERS
POWDERS
PYROLYSIS
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
STRESSES
TRANSMISSION ELECTRON MICROSCOPY