三维编织石英纤维热密封材料气密性能研究

引入三维编织石英纤维织物作为热密封材料,对三维四向、三维五向编织结构热密封材料试样进行了不同压缩率下透气性能试验。分析了三维编织结构热密封材料气体渗透量随压缩率、压差及编织工艺参数的变化规律。结果表明,通过优化编织结构,有利于提高试样的气密性能;试样的平均气体渗透量受纤维体积含量影响,随压缩率的增大而降低;在压缩率为10%与20%时,纤维体积含量为50%的三维四向试样相比气密性能更好,平均气体渗透量分别为1.14×10~(-6)、9.29×10~(-7)kg/(s·mm);当压缩率增加到30%时,试样出现明显剪切变形和碎裂,试样失效。通过合理设计,三维编织石英纤维织物可满足密封材料气密性能要求。

Experimental investigation on air permeability of 3D braided thermal sealing materials with quartz fiber

3D braided quartz fiber preforms were introduced as thermal seals. Air permeability test of the 3D 4-directional and 3D 5-directional braided thermal seals was carried out at room temperature with different compression ratio.Influence of compression ratio,pressure and braided parameters on air permeability of 3D braided thermal seal was analyzed.The results show that:air perme-ability of the sample can be improved by optimizing the structure parameters;By the influence of fiber volume fraction,air permeabil-ity decreases with the increase of compression ratio;The 3D 4-directional samples with 50% fiber volume fraction show better air tightness at the compression ratio of 10% and 20%,and the average air permeability is 1.14×10-6 and 9.29×10-7 kg/(s·mm);When the compression ratio is up to 30%,specimens show significant shear deformation and fragmentation, and fail.In summary, 3D braided preforms could meet the air permeability requirement of thermal seals.