{Reference Type}: Journal Article {Title}: Anisotropic, biomorphic cellular Si3N4 ceramics with directional well-aligned nanowhisker arrays based on wood-mimetic architectures {Author}: XU, Songsong; ZHOU, Xiaonan; ZHI, Qiang; GAO, Junjie; HAO, Liucheng; SHI, Zhongqi; WANG, Bo; YANG, Jianfeng; Kozo, ISHIZAKI {Journal}: Journal of Advanced Ceramics {ISBN/ISSN}: 2226-4108 {Year}: 2022 {Volume}: 11 {Issue}: 4 {Pages}: 656-664 {DOI}: 10.1007/s40145-021-0555-1 {Keywords}: anisotropic {Keywords}: wood {Keywords}: silicon nitride {Keywords}: carbothermal reduction nitridation (CRN) {Keywords}: nanowhisker arrays {Abstract}: 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. {URL}: https://www.sciopen.com/article/10.1007/s40145-021-0555-1 {Language}: en