Nucleation-controlled freeze casting of preceramic polymers for uniaxial pores in Si-based ceramics

SCRIPTA MATERIALIA

卷:130

Article

Naviroj, Maninpat¹  Wang, Melody M.²  Johnson, Matthew T.²  Faber, Katherine T.² 

[1] Northwestern Univ, McCormick Sch Engn & Appl Sci, Dept Mat Sci & Engn, Evanston, IL 60208 USA

[2] CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA

关键词: Porous material;    Ceramics;    Directional solidification;    Casting;    Ice templating;   

DOI  :  10.1016/j.scriptamat.2016.10.038

来源: Elsevier

【 摘 要 】

A grain-selection template was applied to freeze casting to control nucleation of pore-forming crystals and achieve ceramics with highly aligned pore structures. A polymethylsiloxane preceramic polymer was freeze cast with cyclohexane as a solvent to produce dendritic pores in SiOC. Image analysis and permeability measurements were performed to quantify the influence of various templates on sample properties. Results show that the percentage of porosity aligned along the freezing axis increased from 13.9% without a template to 92.6% with an optimal template. The Darcian permeability constant increased by more than 6-fold, from 3.4 x 10(-12) to 2.1 x 10(-11) m(2). (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free