低温预氧化对PIP-SiC_f/SiC复合材料介电性能的影响  

Effects of Low-temperature Pre-oxidization on Dielectric Properties of PIP-SiC_f/SiC Composites

作　　者：穆阳 李皓[1] 刘宇清[2] 林刚[1] 周万城[3] 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)

机构地区：[1]中国飞行试验研究院航电所,西安710089 [2]南京航空航天大学机械结构力学及控制国家重点实验室,南京210016 [3]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《材料导报》2017年第A02期129-133,共5页Materials Reports

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.

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 

分 类 号：TB34[一般工业技术—材料科学与工程]