基于碳纳米管改性的空间级沥青基碳纤维复合材料

With the continuous improvement of satellite functionality and integration, higher requirements are placed on the mechanical properties and thermal properties of composite materials for platform structures. Traditional PAN-based carbon fiber reinforced composites can no longer meet the demand. Pitch-based carbon fiber reinforced composites are the preferred material for the new generation of satellite platform structures because of their high modulus and high thermal conductivity. However, the pitch-based carbon fiber reinforced composites have poor interlaminar properties could be great potential threats to high reliability and long life on-orbit service of spacecraft structure. For this reason, this project develops a new space-grade pitch-based carbon fiber reinforced composite based on carbon nanotubes modification. According to the requirements of high modulus, high thermal conductivity, and low vacuum volatility of satellite structural materials, the composite system and lay-up were designed to study the regulation of macroscopic properties of carbon nanotube film structure morphology, reveal the mechanism of interfacial reinforcement effect of carbon nanotubes on pitch-based carbon fiber composites, explore composite material defect control methods, verify the space environment adaptability of composite materials, and finally realize the new space-level mechanical and thermal composite performance composite materials, to provide technical support for the selection and space application of spacecraft structural materials.

随着卫星功能性和集成化的不断提升，对平台结构复合材料力学性能和热学性能提出更高的要求，传统PAN基碳纤维复合材料已不能满足需求，沥青基碳纤维复合材料以高模量和高导热系数等优点，是新一代卫星平台结构的优选材料，然而沥青基碳纤维复合材料层间性能差，给航天器结构的高可靠长寿命在轨服役带来极大的安全隐患，为此，本项目研制一种基于碳纳米管改性的新型空间级沥青基碳纤维复合材料。根据卫星结构材料高模量、高导热、低真空挥发等要求设计复合材料体系与铺层，开展碳纳米管膜结构形态对复合材料宏观性能调控规律研究，揭示碳纳米管对沥青基碳纤维复合材料的层间强化机理，探索复合材料缺陷控制方法，验证复合材料空间环境适应性，实现新型空间级力学和热学综合性能复合材料的构建，为航天器结构材料的选型和空间应用提供技术支撑。

本项目研制了一种基于碳纳米管改性的空间级沥青基碳纤维复合材料的铺层方法和研制工艺。通过优化沥青基碳纤维复合材料的制备工艺，获得表面无缺陷，无分层现象，其内部碳纳米管具备一定取向的空间级沥青基碳纤维复合材料样件。该复合材料样件具备优良的力学性能和导热性能。.通过力学性能实验证明改性后的沥青基碳纤维复合材料较未改性的样品力学性能有了明显提高，其中弯曲强度提升13.6%-20%，短梁剪切强度提升10.8%-15%。.通过样件导热性测试改性后样件延纤维方向导热率（两方向平均值）较未改性沥青基碳纤维复合材料样件提高约6%-12.9%。.通过真空环境温度冲击试验验证，包括未改性的沥青基碳纤维复合材料和两种含量的碳纳米管改性的沥青基碳纤维复合材料在内，所有样品表面均为产生明显损伤，力学性能较未经过温度冲击试验的样件未发生明显变化。.沥青基碳纤维复合材料具有高模量和高导热性能，优于目前航天器通常采用的PAN基碳纤维复合材料。但是由于沥青基碳纤维本身的缺陷，使其综合评价无法满足航天应用需求。本项目研制的基于碳纳米管改性的空间级沥青基碳纤维复合材料，大大提高沥青基碳纤维复合材料缺陷性能，同时更好地增强其优势性能，满足航天器多功能、高载荷和集成化的不断提升的需求，为大型多功能航天器结构材料选型和空间应用提供技术支撑。