3D printing“wire-on-sphere”hierarchical SiC nanowires/SiC whiskers foam for efficient high-temperature electromagnetic wave absorption  

作　　者：Xinyuan Lv Fang Ye Laifei Cheng Litong Zhang 

机构地区：[1]Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Journal of Materials Science & Technology》2022年第14期94-104,共11页材料科学技术（英文版）

基　　金：supported by the National Science and Technology Major Project(No.2017-I-0007-0077);the National Natural Science Foundation of China(Nos.52072304,51632007,52102113);the 111 Project of China(No.B08040)。

摘　　要：Electromagnetic wave absorption(EWA)materials for use in extreme environments are of great interest.Herein,SiC nanowires/SiC whiskers(SiC_(nw)/SiC_(w))foam with unique“wire-on-sphere”hierarchical structure was developed for efficient high-temperature EWA.SiC_(w)were assembled to porous SiC_(w)spheres via spray drying and then SiC_(w)spheres were 3D printed to SiC_(w)foam.The catalyst-free precursor infiltration pyrolysis process was first developed to ensure that SiCnwcan intentionally grow in situ on the surface of SiC_(w)spheres,thereby achieving“wire-on-sphere”hierarchical structure foam.At room-temperature,the maximum electromagnetic wave effective absorption bandwidth(EAB_(max))and minimum electromagnetic wave reflection coefficient(RC_(min))of SiC_(nw)/SiC_(w)foam can reach 4 GHz and-57 dB,respectively.At600℃,the EAB_(max)and RC_(min) were 3 GHz and-15 dB,respectively.Furthermore,even oxidized at 1000-1500℃,SiC_(nw)/SiC_(w)foam can still retain EAB_(max)ranging from 2.7 to 3.9 GHz and RC_(min)ranging from-16 dB to-64 dB,because the formation of SiO_(2)layer with appropriate thickness can boost interfacial polarization and regulate impedance matching.The SiC_(nw)/SiC_(w)foam also shows the flexural strength as high as 17.05 MPa.All results demonstrate that the SiC nw/SiC_(w)foam is a promising EWA material for applications of harsh environments.And the material-independent“wire-on-sphere”hierarchical structure and its novel preparation process should find the widespread use in the design and fabrication of high-efficiency EWA micro-nano materials.

关 键 词：“wire-on-sphere”hierarchical structure SiC nanowires SiC whiskers 3D printing High-temperature electromagnetic wave ABSORPTION 

分 类 号：TB34[一般工业技术—材料科学与工程] TP391.73[自动化与计算机技术—计算机应用技术]