摘要
熔融石英陶瓷材料由于其低膨胀系数、低导热系数、低介电常数及介电损耗、耐腐蚀以及热稳定性好等优点被认为是新型飞行器天线罩的潜在材料.通过对熔融石英天线罩在短时热冲击试验前后的材料性能进行对比,以及对材料性能测试、扫描电镜及XRD开展分析,发现由于热冲击时扩散迁移行为,使熔融石英颗粒熔融连接成片,显著提高了材料的弯曲强度.同时,试验后材料密度、线膨胀系数、比热容、介电性能等未发生明显变化.
Abstract
Being low at expansion coefficient,low at heat-conductivity coefficient,low at permittivity and at dielectric loss,good in corrosion resistance,and high at thermal-stability,fused silica is sometimes thought of as being the promising candidate for radome in aero-craft.In the present study,researchers re-veal the influence of thermal-shock experiment on the material properties of fused silica radome via me-chanical/thermal tests,scanning electron microscopy,and X-Ray diffraction.It is found that mechanical strength of fused silica is incremental after thermal-shock experiment.And the reason is that the occur-rence of diffusion migration happens during the experiment to make the fused silica particles fused and re-combined flakily.In addition,the effects of thermal-shock experiment on expansion coefficient,heat-con-ductivity,permittivity and dielectric loss are comparatively minor.
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