无机材料学报 ›› 2019, Vol. 34 ›› Issue (10): 1103-1108.DOI: 10.15541/jim20180580 CSTR: 32189.14.10.15541/jim20180580

• 研究论文 • 上一篇    下一篇

Fe2O3对原位制备SiCw/SiC太阳能储热陶瓷的结构与性能的影响

徐晓虹,田江洲,吴建锋,张乾坤,金昊,杜怿鑫   

  1. 武汉理工大学 材料科学与工程学院, 武汉 430070
  • 收稿日期:2018-12-12 修回日期:2019-03-12 出版日期:2019-09-23 网络出版日期:2019-05-29
  • 作者简介:徐晓虹(1963-), 女, 教授. E-mail: xuxh@whut.edu.cn
  • 基金资助:
    国家重点研发计划(2018YFB1501002)

Fe2O3 on In-situ Synthesized SiCw/SiC Composite Ceramics for Solar Thermal Energy Storage

XU Xiao-Hong,TIAN Jiang-Zhou,WU Jian-Feng,ZHANG Qian-Kun,JIN Hao,DU Yi-Xin   

  1. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
  • Received:2018-12-12 Revised:2019-03-12 Published:2019-09-23 Online:2019-05-29
  • Supported by:
    National Key R&D Program of China(2018YFB1501002)

摘要:

为调控SiCw/SiC复相陶瓷中原位生长SiC晶须的生长发育和形貌, 以提高SiC复相储热陶瓷的性能, 在CF0配方(SiC 69.31wt%, AlN 20.30wt%, Si 10.39wt%)的基础上添加0.5wt%~2.0wt% Fe2O3作为催化剂。研究了Fe2O3对晶须形貌、生长机制及SiC复相陶瓷结构与性能的影响。研究结果表明, 引入Fe2O3后晶须生长机制由气-固机理转变为气-液-固机理。Fe2O3添加量通过调节C元素在Fe-Si熔球中的溶解度, 与烧成温度共同调控晶须形貌。经1500 ℃烧成的CF4(2.0wt% Fe2O3)样品性能最佳, 晶须直径50~100 nm, 长度1~6 μm, 其体积密度、抗折强度、比热容分别为2.19 g/cm 3、45.08 MPa、0.95 J/(g·K) (25 ℃), 热导率达18.15 W/(m·K) (25 ℃), 相比于未添加Fe2O3的样品增加了169%。气-液-固机理生长的SiC晶须缺陷少、直径大, 可有效降低晶须-基体传输势垒, 具有更好的热学性能。

关键词: Fe2O3, SiC晶须, SiCw/SiC复相陶瓷, 太阳能储热

Abstract:

In order to improve solar thermal storage properties of the SiCw/SiC composite ceramics, in-situ growth and morphology of SiC whiskers (SiCw) were controlled by adding catalyst Fe2O3(0.5wt%-2.0wt%) on the basis of formula CF0 (SiC 69.21wt%, AlN 20.30wt%, Si 10.39wt%). Effect of Fe2O3 on morphology of SiCw as well as growth mechanism and properties of SiC composite ceramics were analyzed. Results indicated that SiCw growth mechanism changed from vapor-solid to vapor-liquid-solid after adding Fe2O3. The addition of Fe2O3 via adjusting solubility of C element into Fe-Si droplets, as well as firing temperature jointly controlled morphology of SiCw. The sample CF4 (Fe2O3 2.0wt%) fired at 1500 ℃ with whiskers diameter of 50-100 nm and 1-6 μm in length obtained optimal performance, the bulk density, bending strength, heat capacity and thermal conductivity were 2.19 g/cm 3, 45.08 MPa, 0.95 J/(g·K) (25 ℃), 18.15 W/(m·K) (25 ℃), respectively. The value of thermal conductivity increased by 169% compared to the sample without Fe2O3. The few defects and large-diameter of whisker grown by vapor-liquid-solid mechanism could improve thermal properties by reducing the matrix-whisker thermal barrier.

Key words: Fe2O3, SiC whiskers, SiCw/SiC composite ceramics, solar thermal energy storage

中图分类号: