Journal of Inorganic Materials ›› 2013, Vol. 28 ›› Issue (4): 363-368.DOI: 10.3724/SP.J.1077.2013.12282

• Orginal Article • Previous Articles     Next Articles

Research on Microstructures and Properties of in-situ Synthesis of TiB2-TiC0.8-SiC Multiphase Ceramics

SUN Pei-Qiu, ZHU De-Gui, JIANG Xiao-Song, SUN Hong-Liang, XIA Zhao-Hui   

  1. (Key Laboratory of Advanced Technology of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031, China)
  • Received:2012-05-03 Revised:2012-06-12 Online:2013-04-10 Published:2013-03-20
  • About author:SUN Pei-Qiu. E-mail: cheers20080808@126.com

Abstract:

TiB2-TiC0.8-SiC multiphase ceramics were prepared by in-situ hot-pressing sintering. The phase composition and microstructures of the materials were characterized by optical microscope, X-ray diffraction technology and scanning electron microscope. The effects of sintering temperature on the phases, microstructures and mechanical properties of the ceramics were investigated. The results show that with the increase of sintering temperature, density, bending strength and fracture toughness of the ceramics are increasing significantly in the temperature from 1700℃ to 1950℃. Fully densified in-situ TiB2-TiC0.8-SiC multiphase ceramics with well-developed and optimized microstructure are obtained after sintered at 1900℃, in which the uniform distribution of lath-shape TiB2 and bulk TiC0.8 grains is obvious. The present study shows that Vickers hardness, fracture toughness and flexural strength of the TiB2-TiC0.8-SiC multiphase ceramics sintered at 1900℃ are 23.6 GPa, (7.0±1.0) MPa·m1/2 and 470.9 MPa, respectively. When sintering temperature was up to 1950℃, TiB2 and TiC0.8 grains grew up, and therefore the bending strength of multiphase ceramics was reduced. TiB2,TiC0.8 and SiC particles were incorporated to improve the particulate strength and toughness of composite material by the synergistic action of the mechanisms such as crack deflection, grain's pull-out and fine-grain toughening.

Key words: in-situ synthesis, hot-pressing, multiphase ceramics, TiB2-TiC0.8-SiC

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