Journal of Inorganic Materials ›› 2017, Vol. 32 ›› Issue (5): 502-508.doi: 10.15541/jim20160429

• Orginal Article • Previous Articles     Next Articles

Effect of Forming Pressure on Microstructure and Mechanical Properties of SiC/TiB2 Composites

Cui-Ping ZHANG(), Xiang-Wei GAO, Hong-Qiang RU(), Wei-Kang SUN, Jing-Hui ZHU, Hui ZONG   

  1. Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China
  • Received:2016-07-18 Revised:2016-10-08 Online:2017-05-20 Published:2017-05-02
  • About author:ZHANG CUI-PING. E-mail: zhangcp@smm.neu.edu.cn
  • Supported by:
    National Natural Science Foundation of China (51602041, 51272039);Fundamental Research Funds for the Central Universities (N150203001, L1502043)

Abstract:

SiC/TiB2 composites were fabricated by infiltration of molten silicon (Si) into porous preforms containing titanium diboride (TiB2) and free carbon (C) at 1550℃ for 30 min. And the influences of forming pressure on the phase compositions, microstructure, density and mechanical properties of SiC/TiB2 composites were investgated. It is found that forming pressures have significant influence on the microstructure and mechanical properties of SiC/TiB2 composites. XRD results show that the composites consist of TiB2, SiC and Si phases. The microstructure analysis show that the TiB2 and SiC phases distribute in the composite uniformly, with free Si fills in the continuous gaps between TiB2 and SiC phases. TiB2 particle size and volume fraction of free Si both decrease with the increase of forming pressures. The mechanical properties of SiC/TiB2 composites are improved initially and then deteriorated with the increase of forming pressures. Under the optimal pressure of 200 MPa, Vikers-hardness, flexural strength and fracture toughness of the obtained SiC/TiB2 composite are (21.0±1.1) GPa, (354±16) MPa and (6.8±0.2) MPa·m1/2, respectively. The open porosity and bulk density of the obtained SiC/TiB2 composite prepared at 200 MPa forming pressure are 0.90% and 3.63 g/cm3.

Key words: SiC/TiB2 composite, Si infiltration, forming pressure, microstructures, mechanical properties

CLC Number: 

  • TB332