Abstract
Considering the challenge of aerodynamic heating,the development of high-performance insulating ce-ramic materials with lightweight and low thermal conductivity is crucially important for aerospace vehi-cles to achieve flight at high speed for a long time.In this work,macro-porous silicon oxycarbide(SiOC)ceramics with directional pores(DP-SiOC)(mean pore size of 88.1 μm)were prepared using polysiloxane precursors via freeze casting and photocrosslinking,followed by pyrolysis.The DP-SiOC samples were lightweight(density～0.135 g cm-3)with a porosity of 90.4％,which showed good shapability through the molding of polysiloxane precursors.The DP-SiOC samples also exhibited an ultra-low thermal con-ductivity of 0.048 W(m K)-1 at room temperature,which can also withstand heat treatment at 1200 ℃ for 1 h.In addition,scaffolds with triply periodic minimal surfaces(TPMS)were fabricated using digital light processing(DLP)printing,which was further filled with polysiloxane precursors for increasing the strength of DP-SiOC.The TPMS scaffolds filled with macro-porous SiOC ceramics(TPMS-DP-SiOC)showed good integration between TPMS and macro-pore structures,which had a porosity～75％and high specific strength of 9.73 × 103 Nm kg-1.The thermal conductivity of TPMS-DP-SiOC samples was 0.255 W(m K)-1 at room temperature.The biomimetic TPMS-DP-SiOC ceramics developed in this study are likely used for thermal protection systems.
基金项目
CAS Interdisciplinary Innovation Team Projectof the Chinese Academy of Sciences,China(JCTD-2020-10)
Defense Industrial Technology Development Program(JCKY2021130B039)
NETL
NSTL
万方数据