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Imaging the interphase of carbon fiber composites using transmission electron microscopy:Preparations by focused ion beam, ion beam etching, and ultramicrotomy

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Chinese Journal of Aeronautics 2015年第5期28卷 1529-1538页

作者： Wu Qing Li Min gu yizhuo Wang Shaokai Zhang Zuoguang Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beihang University

Three sample preparation techniques, focused ion beam （FIB）, ion beam （IB） etching, and ultramicrotomy （UM） were used in comparison to analyze the interphase of carbon fiber ＇epoxy composites using transmission electron microscopy. An intact interphase with a relatively uniform thickness was obtained by FIB. and detailed chemical analysis of the interphase was investigated by electron energy loss spectroscopy. It shows that the interphase region is 200 mn wide with an increasing oxygen-to-carbon ratio from 10% to 19% and an almost constant nitrogen-to-carbon ratio of about 3%. However, gallium implantation of FIB tends to hinder fine structure analysis of the interphase. For IB etching, the interphase region is observed with transition morphology frona amorphous resin to nano-crystalline carbon fiber, but the uneven sample thickness brings difficulty for quantitative chemical analysis. Moreover, UM tends to cause damage and/or deformation on the interphase. These results are meaningful for in-depth understanding on the interphase characteristic of carbon fiber composites.

关键词： Carbon fiber compositeChemical analysis Focused ion beams lnterphase Ion beam etching Microstructure Ultramicrotomy

Investigation of carbon fiber composite stiffened skin with vacuum assisted resin infusion/prepreg co-curing process

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Science China(Technological Sciences) 2014年第10期57卷 1956-1966页

作者： MA XuQiang gu yizhuo LI Min LI YanXia ZHANG Zuoguang Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education) School of Materials Science and EngineeringBeihang University

Co-cured vacuum assisted resin infusion process(co-VARI process),which combined vacuum assisted resin infusion(VARI)with prepreg vacuum bag only process(VBO),was adopted to fabricate T-shaped stiffened skin with non-crimp fabric(NCF)stiffener and prepreg skin.During compaction stage of co-VARI process,prepreg resin impregnated fiber fabric under elevated temperature and vacuum pressure.This phenomenon was characterized by fluorescent micrographs with different holding temperature and time.Its influences on processing quality and mechanical performance for co-VARI stiffened skin with different filler materials at triangular region were further analyzed by optical micrographs and pull-off test,respectively.The results show that increasing holding temperature and prolonging holding time can promote prepreg resin impregnation in fiber fabric.Moderate prepreg resin impregnation is favorable to reduce resin rich region and increase fiber volume fraction at prepreg-fabric interface.Moreover,prepreg resin impregnation effect plays significant roles on pull-off performance for co-VARI stiffened skin with fabric filler but has negligible influences on specimens with prepreg filler.In addition,compared with stiffened skin with fabric filler,superior processing quality and pull-off performances are achieved for co-VARI stiffened skin with prepreg core filler.These results are helpful to optimize processing procedures and fabricate composite structure by coVARI process.

关键词：树脂浸渍预浸料碳纤维复合材料真空袋皮肤固化过程 VARI 纤维织物

Influence of processing temperature on interfacial behavior of HKT800 carbon fiber with BMI and epoxy matrices

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Chinese Journal of Aeronautics 2015年第4期28卷 1255-1262页

作者： Gao Aijun gu yizhuo Wu Qing Yuan Chao Li Min Zhang Zuoguang Key Laboratory of Aerospace Advanced Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beihang University

This paper aims to study the effect of processing temperature on interfacial behavior of HKT800 carbon fiber composites with epoxy and Bismaleimide（BMI） matrix.Referring to the processing conditions of the composite, various processing-heat treatments were conducted on HKT800 and the extracted sizing content declines with increasing temperature.Chemical analysis shows that the HKT800 sizing is epoxy-type and reactive at 200 C.The interfacial shear strength（IFSS） of HKT800/epoxy and HKT800/BMI was investigated by micro-droplet method, for which the composites were fabricated with modeling temperature schemes referring to different diffusion, cure and post-cure stages.It shows that diffusion temperature and conversion degree of the resin both enhance the interfacial adhesion of HKT800/epoxy composite.For the HKT800/BMI composite,the diffusion temperature shows a insignificant effect on the IFSS.FTIR analysis indicates that sufficient reactions are achieved between HKT800-sizing and epoxy resin, however only partial reactions are observed between the sizing and BMI.Moreover, the presence of the sizing can evidently improve the wettability of HKT800 with epoxy resin but is unfavorable for HKT800 with BMI.

关键词： Bismaleimide Carbon fiber Epoxy Interfacial shear strength Temperature scheme

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蜂窝夹层声衬材料宽频吸声性能优化

复合材料学报 2024年第3期41卷 1290-1299页

作者：罗靓白鹤宇叶卓然顾轶卓北京航空航天大学材料科学与工程学院北京100191 北京北航天宇长鹰无人机科技有限公司北京100191 北京航空航天大学前沿科学技术创新研究院北京100191

针对目前大涵道比涡扇发动机宽频随机的噪声特点,对传统单自由度蜂窝夹层声衬材料进行了结构优化,提升其吸声性能。在保持声衬单自由度蜂窝夹层结构基本形式不变的前提下,为拓宽吸声频谱、达到两个甚至两个以上的特征频率,在单层蜂窝芯... 详细信息

针对目前大涵道比涡扇发动机宽频随机的噪声特点,对传统单自由度蜂窝夹层声衬材料进行了结构优化,提升其吸声性能。在保持声衬单自由度蜂窝夹层结构基本形式不变的前提下,为拓宽吸声频谱、达到两个甚至两个以上的特征频率,在单层蜂窝芯内部特定位置复合碳纳米管薄膜,同时为了提高吸声效果,通过快捷的工艺组装,在多孔板和蜂窝芯之间引入金属丝网和柔性多孔材料,并探究了引入材料的放置位置和参数对于声衬材料吸声性能的影响。实验结果显示,孔径37μm的金属丝网置于多孔面板后、15 mm厚的三聚氰胺海绵放置在多孔面板和蜂窝之间、开孔率为2%和4%的碳纳米管薄膜放置在蜂窝夹层结构内近中间位置的吸声性能最好。基于该结果制备的声衬吸声性能优异,在800 Hz到4 500 Hz范围内表现出良好的吸声性能,两个特征频率的峰值吸声系数分别达到0.98和0.99,平均吸声系数达到0.89,相比优化前提升61.8%,同时半峰宽度能够完全覆盖测试的800 Hz到4 500 Hz频率范围,具有良好的宽频降噪特性。

关键词：蜂窝夹层结构吸声材料声衬吸声系数发动机噪声

Influence of Surface State on Moisture Sensitivity of Carbon Fiber and Its Composite Interfacial Properties

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Journal of Wuhan University of Technology(Materials Science) 2016年第4期31卷 757-764页

作者：王星星李敏 wu qing gu yizhuo li yanxia wang shaokai zhang zuoguang Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beihang University Beijing 100191 China

The influence of surface state on the moisture sensitivity of carbon fiber was analyzed by applying a T800 grade carbon fiber with five different surface conditions,namely,with and without surface oxidation,in the presence or absence of sizing agent.The interfacial properties of their composites in the presence of two epoxy matrices（respectively EP07 and EP10） were also characterized by micro-droplet tests.The overall results show that both oxidized and sizing-coated fibers have higher moisture equilibrium content than that of the pristine unsurface-treated fiber,due to higher amount of activated carbon groups.After moisture absorption of the carbon fibers,almost all the fiber/epoxy systems show decrease in the interfacial shear strength and the unsurface-treated fiber system exhibits the largest decline.Moreover,both interfacial shear strength and interlaminar shear strength of carbon fiber/EP10 composite demonstrate better water resistance performance than that of the carbon fiber/EP07 composite,consistent with DSC results of the two resins.

关键词： moisture sizing epoxy resins interfacial coated sized curing applying droplet

EMS诱变菜豆子叶节定向筛选耐羟脯氨酸(HYP)突变体

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长江蔬菜 2024年第10期 56-59页

作者：许莹楠刘艳军黄俊轩韩启厚古瑜高逸卓天津农学院园艺园林学院天津300392 天津科润农业科技股份有限公司蔬菜研究所/蔬菜种质创新国家重点实验室/天津市蔬菜遗传育种企业重点实验室天津市农业科学院

以双丰一号菜豆子叶节为外植体,利用化学诱变剂EMS处理引发基因突变,进行突变体定向筛选抗逆突变细胞系。以0.17%EMS诱变处理2 h,子叶节的不再生率接近50%;以羟脯氨酸最大致死量3.5 mmol/L为筛选压力,定向筛选抗逆突变体。结果显示,在... 详细信息

以双丰一号菜豆子叶节为外植体,利用化学诱变剂EMS处理引发基因突变,进行突变体定向筛选抗逆突变细胞系。以0.17%EMS诱变处理2 h,子叶节的不再生率接近50%;以羟脯氨酸最大致死量3.5 mmol/L为筛选压力,定向筛选抗逆突变体。结果显示,在羟脯氨酸筛选培养基上,经EMS诱变的子叶节存活31个,突变率为8.61%,存活的子叶节再生率为74.19%,成功获得耐羟脯氨酸的突变株系。

关键词： EMS诱变羟脯氨酸抗逆突变体

生长素和细胞分裂素诱导植物胚性愈伤组织研究进展

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长江蔬菜 2024年第4期 33-37页

作者：许莹楠刘艳军黄俊轩韩启厚高逸卓鲁铭颖古瑜天津农学院园艺园林学院天津300392 天津科润蔬菜研究所/蔬菜种质创新国家重点实验室/天津市蔬菜遗传育种企业重点实验室天津市农业科学院

植物胚性愈伤组织在植物研究与应用中是一种重要的试材,有很多关于植物胚性愈伤组织诱导方法研究的报道。生长素和细胞分裂素被广泛应用于胚性愈伤组织的诱导,是胚性愈伤组织诱导的关键因子。阐述了生长素和细胞分裂素在植物胚性愈伤组... 详细信息

植物胚性愈伤组织在植物研究与应用中是一种重要的试材,有很多关于植物胚性愈伤组织诱导方法研究的报道。生长素和细胞分裂素被广泛应用于胚性愈伤组织的诱导,是胚性愈伤组织诱导的关键因子。阐述了生长素和细胞分裂素在植物胚性愈伤组织诱导及体细胞胚胎发生过程中的作用,讨论了其在植物胚性愈伤组织诱导中的作用、使用方法与原则,为愈伤组织诱导、愈伤组织胚性化诱导等研究中植物生长调节剂的使用提供依据。

关键词：生长素细胞分裂素胚性愈伤组织植物激素植物生长调节剂

超高分子量聚乙烯纤维及其复合材料的研究现状与分析

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复合材料学报 2022年第9期39卷 4286-4309页

作者：叶卓然罗靓潘海燕顾轶卓北京北航天宇长鹰无人机科技有限公司北京100191 北京航空航天大学前沿科学技术创新研究院北京100191

超高分子量聚乙烯(UHMWPE)纤维与碳纤维和芳纶纤维并称当今三大高性能纤维,具备低密度、高抗冲击性能、高断裂强度和模量的特性,同时拥有优异化学稳定性。本文综述了UHMWPE纤维及其复合材料的研究现状和最新进展,包括UHMWPE纤维和其他... 详细信息

超高分子量聚乙烯(UHMWPE)纤维与碳纤维和芳纶纤维并称当今三大高性能纤维,具备低密度、高抗冲击性能、高断裂强度和模量的特性,同时拥有优异化学稳定性。本文综述了UHMWPE纤维及其复合材料的研究现状和最新进展,包括UHMWPE纤维和其他几种高性能纤维的性能对比,UHMWPE纤维的典型生产工艺及其对纤维性能的影响,与UHMWPE纤维匹配的树脂基体种类,提高纤维表面粘结性能、耐热性能和抗蠕变性能的改性方法,纤维织造与复合工艺及UHMWPE纤维及其复合材料的应用;最后分析了UHMWPE纤维及其复合材料当前存在的主要问题,探讨了未来可能的发展方向。

关键词：超高分子量聚乙烯纤维复合材料力学性能改性应用

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宇航级T800碳纤维复合材料界面调控

北京航空航天大学学报 2023年第8期49卷 2011-2020页

作者：李天舒王绍凯武清顾轶卓李庆辉李敏北京航空航天大学材料科学与工程学院北京100191 陕西科技大学材料科学与工程学院西安710016 北京航空航天大学前沿科学技术创新研究院北京100191

上浆剂对高性能碳纤维(CF)表面的修饰作用及对其复合材料界面性能的调制作用至关重要。以湿法制备的宇航级T800碳纤维为研究对象,分析上浆前后纤维表面微结构、化学组成和化学反应特性的变化规律,并对其复合材料的宏微观界面性能进行表... 详细信息

上浆剂对高性能碳纤维(CF)表面的修饰作用及对其复合材料界面性能的调制作用至关重要。以湿法制备的宇航级T800碳纤维为研究对象,分析上浆前后纤维表面微结构、化学组成和化学反应特性的变化规律,并对其复合材料的宏微观界面性能进行表征评价。采用X射线光电子能谱(XPS)、差式扫描量热法(DSC)、傅里叶变换红外光谱(FTIR)等表征方法,分析上浆剂的反应性及其与环氧树脂(EP)、双马来酰亚胺树脂(BMI)的化学反应行为。结果表明:在树脂固化温度条件下上浆剂与纤维表面基团发生化学反应,使得纤维上浆剂提取量及纤维表面活性碳元素含量降低,并且上浆剂与EP、BMI工艺具有良好的化学反应性。经过高温处理后CF表面的上浆剂失活,CF/EP的界面剪切强度发生一定变化,CF/BMI的界面剪切强度下降13%。综上可见:具有化学活性的环氧类上浆剂可明显改善CF表面特性,进而对复合材料的界面性能产生影响,其中上浆剂与树脂体系的反应性对界面亦有影响。

关键词：上浆剂碳纤维化学反应界面调控复合材料