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›› 2008, Vol. 8 ›› Issue (1): 197-201.

• 材料工程专栏 • 上一篇    下一篇

反应烧结制备Si3N4-BN复合材料

袁磊,于景坤   

  1. 东北大学材料与冶金学院,东北大学资源与土木工程学院
  • 出版日期:2008-02-20 发布日期:2008-02-20

Fabrication of Reaction-bonded Si3N4-BN Composite

YUAN Lei,YU Jing-kun   

  1. School of Materials and Metallurgy, Northeastern University,School of resources and civil engineering, Northeastern University
  • Online:2008-02-20 Published:2008-02-20

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被引次数

5

摘要： 以Si粉和BN粉为原料，Fe2O3为烧结助剂，采用反应烧结法于1450℃氮气气氛下制备了Si3N4-BN复合材料. 利用XRD研究了不同烧结制度和BN含量下复合材料的物相组成，利用SEM对材料断面形貌进行了观察，并测定了不同BN含量材料的显气孔率、体积密度和常温抗折强度，同时探讨了Fe2O3的助烧机理和b-Si3N4的形成机理. 研究结果表明，当氮化温度为1450℃、保温时间为45 h时，Si可完全氮化，材料中主晶相仅为Si3N4和BN. 随着BN含量的增加，相对密度和常温抗折强度下降，b-Si3N4含量增多. 当BN含量为30%时，其相对密度为73.3%，抗折强度可达52.5 MPa，同时b/a相比为3.4.

关键词: Si3N4, BN, 反应烧结, 复合材料

Abstract: Si3N4-BN composite was prepared by using Si and BN as raw materials under nitrogen gas flow at 1450℃ by the reaction-sintering method. The phase compositions under different sintering schedules and BN contents were examined with X-ray diffraction analysis. The fracture surface of the composite was investigated by SEM. Apparent porosity, bulk density and bending strength were also measured. And the sintering mechanism under Fe2O3 addition and the formation mechanism of b-Si3N4 were discussed. The results showed that only Si3N4 and BN phases existed in the composite when the sintering schedule was 1450℃ and 45 h. With increasing of BN content, relative density and bending strength decreased and the b-Si3N4 phase increased. When the BN content was 30%, the relative density, bending strength and b-Si3N4/a-Si3N4 phase ratio were 73.3%, 52.5 MPa and 3.4, respectively.

Key words: Si3N4, BN, reaction-sintering, composite