Fabrication of High-Porosity Silicon Nitride Ceramics with Excellent Mechanical Properties

Abstract:

High-porosity silicon nitride ceramics with excellent mechanical properties were fabricated by the carbothermal reduction of SiO₂. The influences of sintering conditions on microstructure and mechanical properties were studied. The results showed that microstructure and mechanical properties of porous silicon nitride ceramics were dependent mostly on the sintering conditions. The sintered porous silicon nitride ceramics exhibited the formation of fibrous microstructure with submicrometer-sized, high-aspect ratio b-Si₃N₄ grains, and uniform pore structure. Porous Si₃N₄ ceramics with a porosity of about 70%, and a flexural strength of about 70 MPa were obtained by sintering at 1750°C, with lower rate of temperature rise and no retaining time. The high strength was attributed to fine, high-aspect ratio b-Si₃N₄ grains and uniform pores between grains.

• Periodical: Advanced Materials Research (Volumes 284-286)
• Pages: 1339-1342
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.284-286.1339
• Online since: July 2011
• Authors: Shao Yun Shan, Qing Ming Jia, Ya Ming Wang, Jin Hui Peng
• Keywords: Ceramic, Mechanical Property, Microstructure, Silicon Nitride

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