摘要
分析了低温预氧化过程对聚碳硅烷(PCS)先驱体结构的影响,研究了不同预氧化温度和时间下SiCf/SiC复合材料室温和高温介电性能的演变规律。结果表明:经预氧化处理后基体中的氧含量增加,生成具有低介电常数的Si CxOy相,且其含量随着预氧化温度的升高或时间的延长逐渐增加,SiC微晶和自由碳的含量均减少,因此SiCf/SiC复合材料的复介电常数明显降低,同时高温复介电常数的升高幅度显著减小。经260℃-6 h预氧化处理后,700℃时复合材料在整个X波段的反射率均达到-8 d B以下,高温吸波性能得到有效改善。
In the present work,the effects of low-temperature pre-oxidation process on the structures of PCS precursor were analyzed,and the evolutions of room-and high-temperature dielectric properties of SiC f/SiC composites at various pre-oxidation temperatures or time were investigated.Results indicate that oxygen content increases in the matrix and SiC x O y phases with low complex permittivity are generated after low-temperature pre-oxidation process.SiC x O y content increases with the increase of pre-oxidation temperatures and time,while both the contents of SiC phase and free carbon decrease,which significantly results in the reduction of complex permittivity of SiC f/SiC composites.In addition,the increasing range of high-temperature complex permittivity is also reduced.After pre-oxidized under 260℃-6 h,the reflection loss of composites at 700℃can be inferior to-8 dB in the whole X band,which indicates that the high-temperature microwave absorbing properties are effectively optimized.
作者
穆阳
李皓
刘宇清
林刚
周万城
MU Yang;LI Hao;LIU Yuqing;LIN Gang;ZHOU Wancheng(Department of Avionics,Chinese Flight Test Establishment,Xi’an 710089;State Key Laboratory on Mechanics and Control of Mechanical Structure,Nanjing University of Aeronautics&Astronautics,Nanjing 210016;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2017年第A02期129-133,共5页
Materials Reports
关键词
SICF/SIC复合材料
低温预氧化
PIP法
高温介电性能
高温吸波性能
SiCf/SiC composites
low-temperature pre-oxidation
PIP process
high-temperature dielectric property
high-temperature microwave absorbing property
