J Mater Sci Technol ›› 2002, Vol. 18 ›› Issue (04): 343-346.

• Research Articles • Previous Articles     Next Articles

Variations of Microstructure and Mechanical Properties of Si-B-O-N Ceramics with Sintering Temperatures

Junbao ZHANG, Guangwu WEN, Tingquan LEI, Dechang JIA, Jiancun RAO   

  1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
  • Received:2001-05-11 Revised:2001-06-06 Online:2002-07-28 Published:2009-10-10
  • Contact: Guangwu WEN

Abstract: Si-B-O-N powder without B-O bonds synthesized by polymeric precursor were hot-pressed into ceramics at different temperatures. The variations of microstructure and mechanical properties of Si-B-O-N ceramics have been investigated. Crystallization of Si-B-O-N ceramics occurred at about 1400°C. Density, elastic modulus, and flexural strength of the ceramics increased with the increasing sintering temperatures, and reached to their maximum values at 1600°C. By contrast,hardness and fracture toughness of the ceramics monotonically changed with increasing sintering temperatures. Hardness decreased, while the fracture toughness increased. The principal toughening mechanisms including crack deflection, crack bridging and plate grain pulling-out effects are discussed

Key words: Si-B-O-N ceramics, Microstructure, Mechanical properties, Toughening mechanisms