Microstructural control of macroporous silicon carbide

Abstract

Wide range of porosity in 30-90 vol% could be created into silicon carbide by employing carefully selected manufacturing methods. Two fabrication methods have been proposed and reviewed in the present paper: (1) partial sintering of submicrometer-sized silicon carbide particle with a suitable amount of sintering additive, acting as an inhibition of grain growth during sintering; (2) the use of ice crystals, as sacrificial pore formers, formed by freezing a silicon carbide particle dispersed gel body, leading to highly porous silicon carbide after sublimating ice crystals by vacuum drying and subsequently sintering. Depending on the processing route adopted, average pore size could be modulated in the range from 0.03 to 0.70 μm and 30 to 150 μm by partial sintering and gelation freezing, respectively. All fabrication methods proposed are simple, economical and versatile to produce macroporous body with tailored pore architecture and engineering porosity. © 2013 The Ceramic Society of Japan. All rights reserved.