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Effect of starting PMMA content on microstructure and properties of gel casting BN/SiN ceramics with spherical-shaped pore structures.
- Source :
- Journal of Materials Science; Nov2013, Vol. 48 Issue 22, p7974-7980, 7p, 2 Diagrams, 3 Charts, 3 Graphs
- Publication Year :
- 2013
-
Abstract
- By gel casting with polymethylmethacrylate microbeads (PMMA) as pore-forming agent, porous boron nitride/silicon nitride (BN/SiN) composite ceramics were successfully prepared. The obtained ceramic shows bimodal hierarchical structures that composed of spherical-shaped micro pores depending on PMMA content and irregular sub-micro pores formed by the stacking of ceramic particles. Porosity of the porous BN/SiN ceramics can be well controlled from 53.0 to 60.6 % by the PMMA content from 10 to 40 wt%, as well as the mechanical and dielectric properties. Effect of PMMA content on phase composition and the relationship between microstructure and the basic properties of the porous BN/SiN ceramics was discussed in detail. Microstructure analysis reveals that the sub-micro pores acted as channels between micro pores. BN particles have a relatively denser distribution on the wall of spherical-shaped micro pores with a window between micro and sub-micro pores, and resulting in a half-closed micro pore structure, which is meaningful for material design with concentration of BN particles on the wall of pore structure. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00222461
- Volume :
- 48
- Issue :
- 22
- Database :
- Complementary Index
- Journal :
- Journal of Materials Science
- Publication Type :
- Academic Journal
- Accession number :
- 89855232
- Full Text :
- https://doi.org/10.1007/s10853-013-7608-y