Microstructural Development of SiC Ceramics by Liquid-Phase Sintering with Spark Plasma Sintering Technique

Abstract:

Sub-micron and nano-sized β-SiC powders were sintered with AlN and Y2O3 as sintering additives by spark plasma sintering (SPS). The sintered densities reached >95% of theoretical with a different molar ratio of AlN to Y2O3 at total amount of 10vol% and temperature of 1900oC for 10min in N2 atmosphere under a pressure of 30MPa. With increasing amount of the AlN additive, the size of SiC grains decreased and the shape changed from globular to columnar. The fully densified SiC at AlN:Y2O3=95:5mol% had an average grain size of 0.5-1µm and 50-100nm in diameter by using sub-micron and nano-sized SiC starting powders, respectively. Flexural strength of the specimen having grain size of 0.5-1µm was approximately 1200MPa at room temperature.

• Periodical: Materials Science Forum (Volumes 510-511)
• Pages: 1022-1025
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.510-511.1022
• Online since: March 2006
• Authors: Mikinori Hotta, Junichi Hojo
• Keywords: Flexural Strength, Liquid Phase Sintering (LPS), Microstructure, Silicon Carbide (SiC), Spark Plasma Sintering (SPS)

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