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常压烧结ZrB2-SiC复相材料的抗氧化行为研究

闫永杰1, 张 辉1,2, 黄政仁1, 刘学建1   

  1. 1. 中国科学院 上海硅酸盐研究所, 上海 200050; 2. 中国科学院 研究生院, 北京 100049
  • 收稿日期:2008-09-16 修回日期:2008-11-23 出版日期:2009-05-20 网络出版日期:2009-05-20

Oxidation Behaviors of the Pressureless Sintered ZrB2-SiC Composites

YAN Yong-Jie1, ZHANG Hui1,2, HUANG Zheng-Ren1, LIU Xue-Jian1   

  1. 1. Shanghai Institute of Ceramics, Chinese Academic of Sciences, Shanghai 200050, China; 2. Graduate University of the Chinese Academy of Sciences, Beijing 100049, China)
  • Received:2008-09-16 Revised:2008-11-23 Published:2009-05-20 Online:2009-05-20

摘要: 以溶胶凝胶法合成的超细ZrB2粉体为主要原料,研究了不同含量Mo和Mo-B4C为烧结助剂时,ZrB2-SiC体系的常压烧结工艺,测试了其力学性能,并系统研究了分别以4wt%Mo和4wt%Mo-2wt%B4C为烧结助剂制备的ZrB2-20wt%SiC复相陶瓷在不同温度下的静态抗氧化行为,研究表明:仅以Mo作为烧结助剂时,在1300℃以上材料表面开始出现ZrO2颗粒析出而迅速氧化. 当添加Mo-B4C复合烧结助剂时,液相保护层在1300℃开始出现,并随着温度升高逐步变厚且均匀,材料在1500℃氧化30min后,抗弯强度仍有室温强度的86%,表现出良好的抗氧化性能.

关键词: 超高温陶瓷, 常压烧结, 抗氧化

Abstract:

The pressureless sintering process of ZrB2-SiC composite ceramics was studied. The ceramic samples was prepared by using sol-gel synthesized ultra-fine ZrB2 powders as sources and different contents of Mo and/or B4C as sintering aids. The static oxidation behaviors of the sintered ZrB2-20wt%SiC composite ceramics using 4wt%Mo and 4wt%Mo-2wt%B4C additives were systemically analyzed. The results show that the composite ceramics oxidized quickly with visible ZrO2 particles on the surface above 1300℃/30min with pure Mo additive. While Mo-B4C additive is added, the protective liquid layer appears at 1300℃ and becomes thicker and uniform with the temperature rising. The composite ceramics present good oxidation resistance of which the flexural strength retains 86% of the value in room temperature after oxidiation at 1500℃ for 30min.

Key words: ultra-high temperature ceramics, pressureless sintering, oxidation resistance

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