Strong effect of atmosphere on the microstructure and microwave absorption properties of porous SiC ceramics
Strong effect of atmosphere on the microstructure and microwave absorption properties of porous SiC ceramics
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气氛对多孔SiC陶瓷微观结构和微波吸收性能的强烈影响
DOI：
10.1016/j.jeurceramsoc.2017.07.034
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发表时间：
2018-01-01
影响因子：
5.7
通讯作者：
Luo, Xiaoguang
中科院分区：
文献类型：
--
作者：
Dong, Shun;Zhang, Xinghong;Luo, Xiaoguang
采用不同聚碳硅烷(PCS)含量的碳化硅/榄烯浆料制备了具有优异微波吸收性能的多孔碳化硅陶瓷。在多孔碳化硅陶瓷孔道中生长的纳米线(NWS)的组成强烈依赖于热解气氛，生成N-2的Si3N4和Ar-SiCNW。随着PCS含量的增加，多孔碳化硅陶瓷在Ar和N-2气氛中的最小反射系数分别从-7.6分贝和-10.9分贝下降到-67.4分贝和-24.7分贝。多孔碳化硅陶瓷在Ar中的有效吸收带宽可达8.1 GHz，在氮气中的有效吸收带宽可达4.5 GHz。多孔性碳化硅陶瓷微波吸收性能的提高归因于纳米碳化硅、纳米碳和纳米碳化钨的形成，纳米碳化硅的形成增加了晶界和缺陷的数量，导致电子偶极极化和界面散射。
Excellent microwave absorption properties of porous SiC ceramics were successfully synthesized using SiC/camphene slurries with various polycarbosilane (PCS) contents related to the SiC powder. The compositions of the nanowires (NWs) growth in the pore channels of porous SiC ceramics strongly depended on the pyrolysis atmosphere, with N-2-generating Si3N4 NWs and Ar SiC NWs. With the increase of PCS content, the minimum reflection coefficient (RC) of porous SiC ceramics decreased from -7.6dB to -67.4 dB in Ar and from -10.9 dB to -24.7 dB in N-2, respectively. The effective absorption bandwidth (EAB) of porous SiC ceramics could be up to 8.1 GHz in Ar and 4.5 GHz in N-2. The enhanced microwave absorption properties of porous SiC ceramics could be attributed to the formation of SiC nano-crystalline, nanosized carbon and the NWs, which would increase the amount of boundaries and defects, leading to the electronic dipole polarization and interfacial scattering.