Silicon Carbide Nanoceramics

Recently, the fabrication of dense SiC bodies with nanosized microstructures has been demonstrated successfully by Zhou et al. [291] and Pan et al. [292], using SPS. 

Fabrication by Liquid-Phase Sintering The preparation of (1-SiC nanoceramics with an average grain size of 110 nm by LPS has been demonstrated by Mitomo et al. [293], who were subsequently awarded a patent on Superplastic SiC Sintered Body [294]. 

Lee et al. [295, 296] achieved a 99% dense LPS-SiC with an average grain size of 4D nm by using a two-step sintering process. Here, nanocrystalline SiC powder with a mean particle size of 20 nm was axially hot pressed with addition of AI2O3, Y2O3 and CaO. The powder compacts were heated to a temperature of1750 °Cand immediately annealed for 8 h at 1550 °C. 

Hotta and Hojo [297] recently fabricated LPS-SiC by SPS with the addition of ALN and Y2O3. After an annealing period of 10min at 1900 °C, a nanosized microstructure (50-100 nm) was obtained which revealed a bending strength as high as 1200 MPa. 

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