BN含量对多孔BN/Si<sub>3</sub>N<sub>4</sub>陶瓷结构和性能的影响

董薇; 汪长安; 尉磊; 欧阳世翕

BN含量对多孔BN/Si₃N₄陶瓷结构和性能的影响

董薇^1,2,
汪长安^2,,
尉磊^2,3,
欧阳世翕¹

1.
中国建筑材料科学研究总院, 北京 100024;
2.
清华大学材料科学与工程系, 新型陶瓷与精细工艺国家重点实验室, 北京 100084;
3.
北京科技大学材料科学与工程学院, 北京 100083

基金项目: 国家自然科学基金(90916025, 90816019, 51172119); 纤维材料改性国家重点实验室(东华大学)资助课题

详细信息

通讯作者:
汪长安, 博士, 教授, 研究领域: 结构陶瓷与陶瓷基复合材料 E-mail: wangca@tsinghua.edu.cn

中图分类号: TQ174
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出版历程
- 收稿日期: 2011-11-28
- 修回日期: 2012-03-27
- 刊出日期: 2013-02-14

Effect of BN content on microstructure and properties of porous BN/Si₃N₄ ceramics

1.
China Building Materials Academy, Beijing 100024, China;
2.
State Key Lab of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
3.
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘要

摘要: 以氮化硅(Si₃N₄)为基体, 氮化硼(BN)为添加剂, 叔丁醇为溶剂, 采用凝胶注模成型与无压烧结工艺(温度为1750 ℃、保温时间为1.5 h、流动N₂气氛), 成功制备出具有一定强度和低介电常数的多孔BN/Si₃N₄陶瓷。在浆料中初始固相含量固定为15%体积分数的基础上, 研究了BN含量对多孔Si₃N₄陶瓷材料的气孔率、物相组成及显微结构的影响, 分析了抗弯强度、介电常数与结构之间的关系。结果表明, 通过改变BN含量可制备出气孔率为55.1%~66.2%的多孔Si₃N₄陶瓷; 多孔BN/Si₃N₄复合陶瓷的介电常数随着BN含量的增加而减小, 为3.39~2.25; 抗弯强度随BN含量提高而有所下降, BN质量分数为2.5%时, 抗弯强度最高, 为(74.8±4.25) MPa。
- BN/Si₃N₄ /
- 多孔陶瓷 /
- 气孔率 /
- 介电常数 /
- 抗弯强度
Abstract: Porous BN/Si₃N₄ ceramics with high strength and low dielectric constant were prepared by tert-butyl alcohol (TBA)-based gel-casting method and pressureless sintering process at 1750 ℃ for 1.5 h in flowing nitrogen. At a fixed solid loading (15%, volume fraction) of the initial slurry, the influence of boron nitride content on the porosity, phase and microstructure was discussed. The relationships among flexural strength, dielectric constant and microstructure were also discussed. The results show that porous BN/Si₃N₄ composite ceramics with high porosity ranging from 55.1% to 66.2% are prepared by adjusting the content of BN. Dielectric constant of porous BN/Si₃N₄ composite ceramics is between 3.39 and 2.25, which shows a decreased trend with the content of BN increasing. Flexural strength decreases with BN content increasing, flexural strength reaches the maximum value (74.8±4.25) MPa, when the mass fraction of BN is 2.5%.
- BN/Si₃N₄ /
- porous ceramic /
- porosity /
- dielectric constant /
- flexural strength