无机材料学报 ›› 2020, Vol. 35 ›› Issue (6): 661-668.DOI: 10.15541/jim20190359

所属专题: 结构陶瓷论文精选(二)

• 研究论文 • 上一篇    下一篇

NiFe2O4陶瓷U型套管的注浆成型和无压烧结

张志刚1,2,卢晓通1,2,刘金莉1,2   

  1. 1. 多金属共生矿生态化冶金教育部重点实验室 东北大学 沈阳 110819
    2. 冶金学院 东北大学, 沈阳 110819
  • 收稿日期:2019-07-13 修回日期:2019-08-13 出版日期:2020-06-20 网络出版日期:2019-09-04
  • 作者简介:张志刚(1983-), 男, 讲师. E-mail: zhangzg@smm.neu.edu.cn;
    ZHANG Zhigang (1983-), male, lecturer. E-mail: zhangzg@smm.neu.edu.cn
  • 基金资助:
    中央高校基本科研业务费专项资金(N182504015)

NiFe2O4 Ceramic U-shaped Sleeve Prepared by Slip Casting and Pressureless Sintering

ZHANG Zhigang1,2,LU Xiaotong1,2,LIU Jinli1,2   

  1. 1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China
    2. School of Metallurgy, Northeastern University, Northeastern University, Shenyang 110819, China
  • Received:2019-07-13 Revised:2019-08-13 Published:2020-06-20 Online:2019-09-04
  • Supported by:
    Fundamental Research Funds for the Central Universities(N182504015)

摘要:

采用注浆成型和无压烧结技术制备铝电解测温热电偶NiFe2O4陶瓷U型保护套管, 对浆料稳定性、生坯烧结行为和组装热电偶的测温性能进行了研究。结果表明: 添加10wt% NiFe2O4纳米粉和5wt%纳米粘结剂能有效提高浆料体系的Zeta电位, pH在10.0~11.0之间时浆料体系的稳定性较好。升温至1100 ℃以上生坯开始大量收缩, 随烧结温度的升高线收缩和线收缩速率逐渐增大, 在1300 ℃时线收缩速率达到最大值; 烧结初期活化能为295.11 kJ·mol -1, 受体积扩散和晶界扩散共同控制。测温结果表明组装热电偶在升降温过程中温度响应及时, 具备良好的抗熔盐腐蚀性能和抗热震性能, 满足工业铝电解测温热电偶套管的要求, 具备工业应用前景。

关键词: 注浆成型, NiFe2O4, 稳定性, 烧结, 腐蚀

Abstract:

Slip casting and pressureless sintering were used to produce NiFe2O4 ceramic U-shaped protection sleeves for thermocouple in aluminum electrolysis. The stability of slurry, sintering behavior of green body as well as the temperature measuring performances, were investigated in detail. The Zeta potential of slurry was improved effectively by adding 10wt% NiFe2O4 nanopowders and 5wt% nano-binder, and the slurry possessed better sedimentation stability when pH was in the range from 10.0 to 11.0. Green bodies began to shrink significantly when the sintering temperature rising to 1100 ℃. The linear shrinkage and linear shrinkage ratio increased with temperature, and the linear shrinkage ratio reached its maximum at 1300 ℃. The sintering activation energy of the initial stage was 295.11 kJ·mol -1, and the main transport mechanisms were volume diffusion and grain boundary diffusion. The temperature testing results showed that the assembled thermocouple with NiFe2O4 ceramic protection sleeves worked well with timely response to temperature variation, as well as good resistance to thermal shock and corrosion from melt salts, with the prospect of industrial temperature measurement applications in an aluminum reduction cell.

Key words: slip casting, NiFe2O4, stability, sintering, corrosion

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