SiC_w/Si_3N_4复合陶瓷的制备及介电性能的研究  

Preparation and Dielectric Properties of SiC_w/Si_3N_4 Composite Ceramic

作　　者：肖伟玲[1,2] 肖鹏[1] 周伟[1] 罗衡[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]航天科工武汉磁电有限责任公司,湖北武汉430080

出　　处：《稀有金属材料与工程》2017年第4期1061-1066,共6页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划("973"计划)(2011CB605804)

摘　　要：采用凝胶注模成型工艺制备了SiC_w/Si_3N_4复合陶瓷,由扫描电镜(SEM)可以看出,随热处理温度升高,碳化硅晶须的长径比逐渐减小;随烧结温度升高,复合陶瓷开孔率降低,密度随晶须含量的增加而增加。研究表明,SiC_w/Si_3N_4复合陶瓷的介电常数实部和虚部随碳化硅晶须含量的增加而升高,当烧结温度为1600℃,晶须含量从5%增加到15%时,8 GHz时介电常数实部从13.4增加到22.8,虚部从0.67增加到4.86;当烧结温度为1750℃时,8 GHz时介电常数实部从9.2增加到21.7,虚部从0.51增加到3.02。由反射率曲线可以看出,烧结温度为1750℃比1600℃时反射衰减随晶须含量的增加向低频移动的更快,频宽更宽。SiCw/Si3N4 （SiC whisker/Si3N4） composite ceramics were prepared by gel-casting. SEM images show that the length-to-diameter ratio of the whiskers decreases with the heat treatment temperature increasing. The open porosity of the composite ceramics declines while the density increases as the whisker content rises when the sintering temperature increases. Both real （ε＇） and imaginary （ε＂） permittivity of SiCw/Si3N4 composite ceramics increase as the whisker content increases in the frequency range of 8.2-12.4 GHz. As the whisker content increases from 5% to 15%, the dielectric constant ε＇ increases accordingly from 13.4 to 22.8 at a frequency of 8 GHz, while ε＂ increases from 0.67 to 4.86 when the sintering temperature is 1600 ℃; the dielectric constant e＇ increases accordingly from 9.2 to 21.7 at a frequency of 8 GHz, while ε＂ increases from 0.51 to 3.02 when the sintering temperature is 1750 ℃ The reflectivity of the composite ceramics with the heat treatment temperature 1750 ℃ moves to a low frequency more quickly and the bandwidth is wider than those of 1600 ℃

关 键 词：SICW SI3N4 复合陶瓷 凝胶注模成型 介电性能 

分 类 号：TQ174.1[化学工程—陶瓷工业]