硕士学位论文硕士学位论文 Cf/改性环氧复合材料低温界面性能及液氧相容性研究 CRYOGENIC INTERFACIAL PROPERTIES AND LIQUID OXYGEN COMPATIBILITY OF CF/MODIFIED EPOXY RESIN 舒舒 鹏鹏 哈尔滨工业大学哈尔滨工业大学 2013 年年 7 月月 国内图书分类号：TG142.1 学校代码：10213 国际图书分类号：621 密级：公开 工工程程硕士学位论文硕士学位论文 Cf/改性环氧复合材料低温界面性能及液氧相容性研究 硕 士 研 究 生 ： 舒 鹏 导 师 ： 刘文博 教授 申请学位 ： 工程硕士 学科 ： 材料工程 所 在 单 位 ： 材料科学与工程学院 答 辩 日 期 ： 2013 年 7 月 授予学位单位 ： 哈尔滨工业大学 Classified Index: TG142.1 U.D.C: 621 Thesis for the Master Degree in Engineering CRYOGENIC INTERFACIAL PROPERTIES AND LIQUID OXYGEN COMPATIBILITY OF CF/MODIFIED EPOXY RESIN Candidate： Shu Peng Supervisor： Prof. Liu Wenbo Academic Degree Applied for： Master of Engineering Speciality： Materials Engineering Affiliation： School of Materials Science and Engineering Date of Defence： July, 2013 Degree-Conferring-Institution： Harbin Institute of Technology 哈尔滨工业大学工程硕士学位论文 - I - 摘 要 未来航天器的发展主要以低成本、高运载能力为目标，例如，低成本航天器(ELV)、比如单级入轨(SSTO)、可重复使用飞行器(RLV)等。要达到这个目标首先要解决的是结构减重问题，而液氧贮箱是飞行器主要的结构部件之一，也是减重的关键部件。碳纤维复合材料(CFRP)属于各向异性材料，具有抗疲劳性优良、 破坏后无二次损伤的特点， 从诞生起便在航空航天领域获得飞速的发展。因此发展复合材料液氧贮箱是航天器实现减重目标的关键技术之一。本文对复合材料在液氧(183)低温条件下的界面性能、层间断裂韧性、液氧相容性进行研究，希望能为复合材料液氧贮箱在低温下的使用性能和可靠性提供理论基础和技术支持。 通过对树脂体系与碳纤维动态接触角测试，研究结果表明树脂胶液能够较好地润湿纤维，形成良好的界面粘结，并且固化反应过程中，在 120温度保持 1h 对纤维和树脂的润湿起到了很好的促进作用。 采用微滴脱粘法对复合材料界面强度进行表征，结果发现在低温条件下界面强度(IFSS)会有明显的提高。 利用 Scheer-Nairn 脱粘模型的剪滞方程计算了微滴脱粘的能量释放率(Gdc)，结果证明 IFSS 的提高以及热应力都可以导致 Gdc的提高。通过对三元体系碳纤维复合材料 II 型层间断裂能量释放率(GIIc)的测试发现，低温条件下 GIIc有明显的提高，通过对比 Gdc与树脂的冲击强度认为深冷下 GIIc的提高主要是由于界面强度的提高带来的更高的破坏能。 复合材料液氧冲击敏感性测试结果显示单次以及重复 2 次冲击结果液氧敏感系数(IRS)值均小于 2%，对边缘冲击结果为 6%，对表面有缺陷的冲击结果显示为不相容，说明缺陷会大大提高复合材料液氧冲击敏感系数；通过对复合材料层合板的冷震循环测试证明高低温循环在 50 次以内的界面强度基本没有变化。对一定次数冷热循环后的试样进行液氧冲击敏感测试，结果发现，25 次之内的冷热循环试样液氧敏感系数相比于循环前会有所升高，但是仍满足液氧相容性；而 25 次冷热循环后，复合材料液氧冲击敏感性大大升高，表现为与液氧不相容。 关键词：碳纤维复合材料；界面；低温；液氧相容性 哈尔滨工业大学工程硕士学位论文 - II - Abstract The development of future aerospace ship aims at low cost and high carrying capacity. Low-cost spacecraft (ELV), Single Stage To Orbit (SSTO) and Reusable Launch Vehicle (RLV) are examples of these aerospace ship. To achieve this goal, the weight of the structure should be lowered. Thus, as the main part of the structure, liquid oxygen tank is the considerable part to lower the weight. CFRP is a kind of anisotropy material applied in the field of aerospace because of its better fatigue resistance and without second damage after break. So development of liquid oxygen tank made of composite material is a key technology to lower the weight. This dissertation focuses on composite materials interfacial property, interlayer fracture toughness, compatibility with liquid oxygen under the circumstance of liquid oxygen (-183 C) to provide theoretical basic and technological support for the usability and reliability of liquid oxygen tank made of composite materials. By testing the dynamic contact angle of resin system and carbon fiber, the research shows that resin glue solution can wet fiber and form a better interfacial adhesion. In the process of curing reaction, the environment of 120 C remaining 1 h can accelerate the wetting of fiber and resin. Micro debonding method is applied to measure the interfacial strength and it shows the interfacial strength would increase significantly under low temperature. The shear lag equation of Scheer-Naim debonding model analyzes the energy release rate (Gdc) of the droplets debonding. The result proves the increase of IFSS and thermal stress can both result to the increase of Gdc. After measurement of the type II interfacial fracture energy release rate (GIIc) of ternary system composite materials, the GIIc increases significantly under low temperature. Compared Gdc and resins impact strength, the increase of GIIc under low temperature is mainly result from the higher energy of rupture brought by the increase of interfacial strength. The oxygen impact sensitivity test of composite materials shows that the IRS of single and double impacts are both less than 2%, compared with edge impact, 6%. The incompatibility of test on surface with defect shows that defect would enhance the composite materials IRS. Cold shock cyclic test of composite plywood proves the interfacial strength changes little within 50 high-low temperature cycles. After 哈尔滨工业大学工程硕士学位论文 - III - IRS test of some as-cold shock cyclic samples, the outcome shows that within 25 temperature cycles, the samples IRS would increase but still compatible with liquid oxygen; after 35 temperature cycles, the composite materials IRS would increase obviously and incompatible with liquid oxygen. Keywords: CFRP, interface, cryogenic, liquid oxygen compatibility 哈尔滨工业大学工程硕士学位论文 - IV - 目 录 摘 要 .I Abstract . II 第 1 章 绪 论 .