CNT薄膜电热原位共固化复合材料板的温度均匀性研究

Temperature uniformity study of electrothermal in-situ co-curing of composite plate with CNT film

碳纳米管(CNT)薄膜电加热原位共固化复合材料是一种免热压罐的高效节能工艺方法,是国家“双碳”战略下制备碳纤维复合材料的新途径。然而,在固化过程中CNT薄膜电加热的不均匀温度分布,易导致复合材料成型质量差,进而限制其应用。为此,研究揭示了CNT薄膜的电加热特性,阐明了加载电压、预浸料层数以及CNT薄膜层数/尺寸对复合材料温度分布的影响规律。结果表明,CNT薄膜具有高电热转换效率和良好的热稳定性,增加CNT薄膜层数和尺寸有利于改善复合材料面内温度分布。对于12层200 mm×180 mm预浸料,采用1.7倍尺寸的双层CNT薄膜可将复合材料固化过程中的面内温差降低至4℃以内,固化度达到99%以上,且相比传统烘箱固化,复合材料的拉伸强度提高了6.99%。研究结果为发展CNT薄膜电热原位共固化复合材料结构的温度均匀调控方法奠定了基础。

Electrically heated in situ co-curing for composite with carbon nanotube(CNT)film is an energy-saving efficient process without autoclave,which is a new way to prepare carbon fiber composite under the national“dual-carbon”strategy.However,the electrothermal inhomogeneous temperature distribution of CNT film during the curing process can easily lead to poor molding quality of the composite and thus limits their applications.Therefore,the electrical heating characteristics of CNT film were revealed,and the effects of loading voltage,the number of prepreg layers,and the CNT film layers/size on the temperature distribution of composite were clarified.The results show that the CNT film has high electro-thermal conversion efficiency and good thermal stability,and increasing the layer number and size of CNT film is conducive to improving the in-plane temperature distribution of the composite.For the 12 layers of 200 mm×180 mm prepreg,the in-plane temperature difference during the curing process of the composite material can be reduced to less than 4℃by using 1.7 times the size of the double-layer CNT film,and the curing degree can reach more than 99%.Compared with the traditional oven curing,the tensile strength of the composite material is increased by 6.99%.The research results lay a foundation for the development of temperature uniform control method for the electrothermal in-situ co-curing of composite structures with CNT film.