Anisotropic,biomorphic cellular Si3N4 ceramics with directional well-aligned nanowhisker arrays based on wood-mimetic architectures

• 作者: Songsong XU Xiaonan ZHOU Qiang ZHI Junjie GAO Liucheng HAO Zhongqi SHI Bo WANG Jianfeng YANG Kozo ISHIZAKI
• 来源期刊: 先进陶瓷（英文版）
• 年，卷（期）: 2022,（4）
• 所属期刊栏目: Rapid Communication
• 页码范围: 656-664
• 页数: 9页
• 语种: 英文

摘要

Inspired by the transport behavior of water and ions through the aligned channels in trees,we demonstrate a facile,scalable approach for constructing biomorphic cellular Si3N4 ceramic frameworks with well-aligned nanowhisker arrays on the surface of directionally aligned microchannel alignments.Through a facile Y(NO3)3 solution infiltration into wood-derived carbon preforms and subsequent heat treatment,we can faultlessly duplicate the anisotropic wood architectures into free-standing bulk porous Si3N4 ceramics.Firstly,α-Si3N4 microchannels were synthesized on the surface of CB-templates via carbothermal reduction nitridation(CRN).And then,homogeneous distributed Y-Si-O-N liquid phase on the walls of microchannel facilitated the anisotropic β-Si3N4 grain growth to form nanowhisker arrays.The dense aligned microchannels with low-tortuosity enable excellent load carrying capacity and thermal conduction through the entire materials.As a result,the porous Si3N4 ceramics exhibited an outstanding thermal conductivity(TC,kR ≈6.26 W·m-1·K-1),a superior flexural strength(σL ≈ 29.4 MPa),and a relative high anisotropic ratio of TC(kR/kL=4.1).The orientation dependence of the microstructure-property relations may offer a promising perspective for the fabrication of multifunctional ceramics.