预制体结构对针刺石英纤维/环氧树脂复合材料导热性能的影响

为了探索预制体结构对针刺石英纤维/环氧树脂复合材料导热性能的影响,采用逐层针刺技术和树脂传递模塑工艺制作了针刺石英纤维/环氧树脂复合材料。利用瞬态热线法测量了环氧树脂和不同预制体结构的针刺石英纤维/环氧树脂复合材料的导热性能。结果表明:随着纤维体积分数的提高,针刺石英纤维/环氧树脂复合材料的导热性能得到了提升。其中,用石英纤维短切毡增强环氧树脂的导热性能比环氧树脂提高了35.9%。当针刺石英纤维/环氧树脂复合材料中的无纬布纤维平行于热线时,采用石英纤维短切毡与石英纤维无纬布共同增强的2种针刺石英纤维/环氧树脂复合材料的导热性能分别比环氧树脂提高了45.5%和46.4%;而当无纬布纤维垂直于热线时,导热性能比环氧树脂分别提高了56.4%和61.8%。针刺石英纤维/环氧树脂复合材料的导热性能不仅受石英纤维体积分数影响,也受到预制体中无纬布纤维体积分数和取向的影响。

Effects of preform structure on thermal conductivity of needle-punched quartz fiber/epoxy composites

In order to investigate the effects of preform structure on thermal conductivity of needle-punched quartz fiber/epoxy composites,the needle-punched quartz fiber/epoxy composites were prepared by needle-punching step by step and resin transfer molding process.The thermal conductivities of epoxy and needle-punched quartz fiber/ep-oxy composites with different preform structures were measured by using transient hot-wire method.Results show that the thermal conductivities of needle-punched quartz fiber/epoxy composites increase with the increase of fiber volume fraction.Compared with epoxy,the thermal conductivity of short-cut quartz fiber web reinforced epoxy in-creases by 35.9%.When hot-wire is parallel to the direction of fibers in the non-woven cloth of needle-punched quartz fiber/epoxy composites,the thermal conductivities of two needle-punched quartz fiber/epoxy composites, which are reinforced by short-cut quartz fiber web and non-woven quartz fiber cloth,increase by 45.5% and 46.4%,respectively.When hot-wire is perpendicular to the direction of fibers in non-woven cloth,the increase of thermal conductivities are 5 6.4% and 6 1.8%,respectively.The thermal conductivity of needle-punched quartz fi-ber/epoxy composites would be affected not only by the quartz fiber volume fraction,but also the volume fraction and orientation of the fiber in the non-woven cloth of preform.