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PVP塑性界面层对CF/VE复合材料性能的影响 总被引:2,自引:0,他引:2
用热塑性聚乙烯吡咯烷酮(PVP)对商用炭纤雏(CF)表面进行不同的涂覆处理后,制备了炭纤维/乙烯基酯树脂基单向复合材料(CF/VE)。研究了PVP塑性界面层对复合材料的层间剪切强度(ILSS)、弯曲性能、断口形貌及动态热机械性能的影响。结果表明。在炭纤维保持原环氧上胶层的基础上直接涂覆PVP时。复合材料的ILSS和弯曲性能提高,纤维与乙烯基酯树脂基体的粘结性能得到改善;炭纤维脱除原环氧上胶层后涂覆PVP时。复合材料的ILSS和弯曲强度降低,纤维与基体的粘结性能变差;塑性PVP界面层的存在使复合材料的玻璃化转变温度(Tg)和弯曲模量提高,储能模量(E’)和能量损耗增大。 相似文献
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树脂基复合材料界面及界面表征 总被引:3,自引:0,他引:3
在树脂基体和成型工艺一定的条件下,碳纤维表面及表面涂层的性质在很大程度上决定了复合材料界面的性质,通过对CF表面进行性改及改变CF表面涂层的性质,可优化界面,最大限度发挥界面的特性,有用了界面微脱粘仪及透射电镜照片伪彩色处理对界面进行直观表征。 相似文献
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本文根据聚醚醚酮(PEEK)在碳纤维表面形式的横晶层的结构特征分析,建立了CF/FEEK复合材料界面层微观力学性能的理论方程,计算了界面层的杨氏模量.通过超声浸渍法测量复合材料的力学性能验证了计算结果,证明所进行的分析合理.计算结果表明,PEEK界面横晶层在垂直于纤维方向的杨氏模量Er随PEEK结晶度的增大,或随横晶中PEEK晶片长度的增大而增大,并随晶片厚度的增大而减小.该界面层的上述模量值始终高于界面层附近球晶的模量值Es,两者之间的比值ET/Es;依赖于横晶及球晶中的晶片长度b、厚度c和宽度a.由于界面层的模量高于非界面层的模量,当复合材料中纤维表面形成横晶时,复合材料将有较高的刚性. 相似文献
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LP-15聚酰亚胺是新一代不含MDA的PRM聚酰亚胺树脂体系。作为复合材料树脂基体,LP-15酰亚胺具有优异的成型工艺性,较 好的抗热氧化和稳定性,优良的综合学性能及耐冷热疲劳性能,可在280℃下替代PMR-15复合材料长期使用。 相似文献
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湿热循环对CCF300/QY8911复合材料界面性能的影响 总被引:2,自引:0,他引:2
通过对CCF300/QY8911复合材料试样进行循环吸湿-脱湿处理,绘制吸湿和脱湿曲线并用Fick第二定律进行拟合,采用层间剪切强度(ILSS)表征不同湿热条件对纤维/树脂界面性能的影响,再通过SEM观察试样剖面和侧面的微观形貌.结果表明:CCF300/QY8911复合材料的吸湿和脱湿行为符合Fick第二定律,试样水浸(水温71℃)14天后达到饱和吸湿率;水对CCF300/QY8911复合材料纤维/树脂界面的破坏分为可逆和不可逆,脱湿处理会消除可逆破坏,使干态ILSS有所回复;湿热循环次数增加会进一步引起纤维/树脂界面产生不可逆破坏,使CCF300/QY8911复合材料ILSS降低,但吸湿是引 相似文献
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本文利用扫描电镜和能谱分析手段,对连续SiC纤维增强钛合金基复合材料的界面热稳定性和界面反应机制进行了分析和研究。 相似文献
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Elastic-plastic and failure properties of a unidirectional carbon/PMR-15 composite at room and elevated temperatures 总被引:2,自引:0,他引:2
A series of off-axis tensile tests at room and elevated temperatures have been conducted up to 316°C (600°F) to determine the elastic and plastic properties of a unidirectional carbon/PMR15 composite as a function of temperature. The transverse tensile and shear strengths of the composite as a function of temperature have also been determined. The effect of the specimen preparation process (type of machining) on the strength properties of the composite has also been evaluated. It has been shown that elastic (with the exception of Poisson ratios ν12 and ν21), plastic, and strength properties of the composite are significantly affected by elevated temperatures. It has also been demonstrated that the quality of machining can noticeably influence the normal and shear strength data at room and elevated temperatures. Even if the quality of machining is very high, failure of the specimens can occur either in the gage or grip sections. At room temperature, all specimens failed in the grip areas influencing the transverse tensile and shear strength measurements. However, the type of specimen failure does not noticeably affect the strength data at elevated temperatures. The transverse tensile and shear strength properties of the composite at room temperature could only be estimated by extrapolating the normal and shear strength vs temperature curves to room temperature. 相似文献
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Y. C. Lu G. P. Tandon D. C. Jones G. A. Schoeppner 《Mechanics of Time-Dependent Materials》2009,13(3):245-260
Polymer matrix composites used in high temperature applications experience material property degradation due to thermal oxidation. In the present paper, the oxidation profiles of the isothermally aged PMR-15 specimens are studied using an optical microscope. Results show that the oxidized specimen exhibits distinguished heterogeneous structure. In addition, the spatial dependent elastic and viscoelastic properties of PMR-15 specimens isothermally aged at various environmental conditions are probed through nanoindentation tests. Results indicate that both elastic modulus and creep strain rate sensitivity of the oxidized surfaces are higher than those of the unoxidized interiors. These results are the consequences of chemical and physical changes that occur during oxidation including chemical bond breakage and outgassing of low-molecular weight species. 相似文献
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Evolution of stress and deformations in high-temperature polymer matrix composites during thermo-oxidative aging 总被引:1,自引:0,他引:1
K. V. Pochiraju G. P. Tandon G. A. Schoeppner 《Mechanics of Time-Dependent Materials》2008,12(1):45-68
This paper presents a model-based analysis of thermo-oxidative behavior in high-temperature polymer matrix composite (HTPMC)
materials. The thermo-oxidative behavior of the composite differs from that of the constituents as the composite microstructure,
the fiber/matrix interphase/interface behavior and damage mechanisms introduce anisotropy in the diffusion and oxidation behavior.
Three-dimensional Galerkin finite element methods (GFEM) that model the thermo-oxidative layer growth with time are used together
with homogenization techniques to analyze lamina-scale behavior using representative volume elements (RVEs). Thermo-oxidation-induced
shrinkage is characterized from dimensional changes observed during aging in inert (argon) and oxidative (air) environments.
Temperature-dependent macro-scale (bulk) mechanical testing and nano-indentation techniques are used for characterizing the
effect of oxidative aging on modulus evolution. The stress and deformation fields in a single ply unidirectional lamina are
studied using coupled oxidation evolution and non-linear elastic deformation analyses. Deformation and stress states are shown
as a function of the aging time. While the thermo-oxidative processes are controlled by diffusion phenomenon in neat resin,
the onset and propagation of damage determines the oxidative response of an HTPMC. 相似文献
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研究了不同界面结合状况的三维编织炭纤维增强环氧树脂复合材料的吸湿行为,通过对炭纤维表面氧化处理提高了复合材料的界面结合强度。对复合材料的断口和吸湿复合材料的表现形貌进行了SEM观察。结果表明,吸湿过程满足Fick扩散;强界面结合抑制了三维编织复合材料吸湿,降低了水的扩散系数。 相似文献
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Effects of moisture and thermal cycling on in-plane shear properties of graphite fibre-reinforced cyanate ester resin composites 总被引:1,自引:0,他引:1
The weight change and retention of in-plane shear (±45°) strength of graphite fibre-reinforced cyanate ester resin matrix composites have been estimated on exposure to high humidity and thermal cycling, respectively. Cyanate ester resin matrix composites absorbed a remarkably small amount of moisture on exposure to high humidity. However, the degree of moisture absorption underwent a rather sudden increase to a new equilibrium level after prolonged exposure. A morphology study showed the occurrence of extensive cracking in the matrix/interface region in the form of delamination between plies as well as translaminar cracking within plies. The phenomenon is believed to be caused by weakening of the fibre-matrix interface, which was confirmed by microscopic analysis of fracture surfaces. A sudden moisture gain associated with extensive matrix/interface cracking was found to reduce the in-plane shear strength and fatigue lifetime at a given stress amplitude. The slope of the S-N curve was lower for wet specimens, implying a higher growth rate of local cracks as well as delamination. The rate of in-plane shear strength degradation was also measured on static exposure to dry heat as well as after thermal cycling to a peak temperature of 150 or 204°C. At a frequency of 10 min/cycle and for a relatively short duration, the effect of thermal cycling seems to be represented by the cumulative sum of thermal oxidation effects at the peak temperature. 相似文献
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通过对玻纤增强环氧乙烯基酯树脂(GF/EVE)和玻璃纤维增强不饱和聚酯树脂(GF/UP)复合材料的多轴向铺层设计试件进行低速冲击、弯曲和剪切破坏性力学试验,分析了不同铺层方式的GF/EVE和GF/UP复合材料冲击、弯曲和剪切载荷作用下产生的损伤及失效模式。结果表明:在铺层设计与工艺相同的情况下,CF/EVE的弯曲强度、冲击韧性均优于CF/UP;[0,90]6试件冲击能量吸收性能优于其他五种铺层方式;铺设角设计、树脂基体类型、铺层厚度对层合板剪切力学性能的影响较小。并基于SEM与超声C扫描成像检测(C-SAM)对复合材料的微观界面脱粘机制及损伤演化行为进行阐释。 相似文献
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分别采用日本东丽T800H和国产T800碳纤维作为增强体,采用热压罐工艺制备双马来酰亚胺树脂基复合材料。研究了2种碳纤维的表面物理和化学状态,复合材料的微观界面性能及力学性能。结果表明:国产T800碳纤维表面沟槽分布较多,表面粗糙度较高,有利于与树脂基体形成更好的物理结合作用。同时,国产T800碳纤维表面具有较多的含氧官能团,有利于与基体树脂形成更好的化学结合作用。因此,国产T800碳纤维的界面剪切强度较T800H碳纤维高约27%。国产T800/HT-280复合材料的力学性能均普遍高于T800H/HT-280复合材料,其中,90°拉伸强度高约25%,面内剪切强度、弯曲强度高约12%,层间剪切强度高约7%。 相似文献
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M40/5228复合材料力学性能研究 总被引:4,自引:0,他引:4
用湿法缠绕技术制作了M40/5228预浸料,对热压灌固化的M40/5228复合材料的室温、高温干态和湿态力学性能进行了研究,用扫描电镜(SEM)对复合材料的界面进行了表征。与M40/4211复合材料相比,M40/5228复合材料的各项力学性能均有很大程度的提高。M40/5228复合材料具有优异的耐湿热性能,在130℃干态和湿态下,其弯曲强度、模量和层剪强度的保持率较高 相似文献
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分别采用混酸、环氧树脂(EP)和硅烷偶联剂对碳纳米管(CNTs)进行功能化处理,用十八烷基三甲基氯化铵对蒙脱土(MMT)进行有机化处理,将具有一维纳米尺度的CNTs和二维纳米尺度的有机化蒙脱土(OMMT)复合引入EP酸酐固化体系,通过溶液共混法制备纳米OMMT/EP、CNTs/EP、CNTs-OMMT/EP复合材料。使用简支梁冲击试验仪测试三种复合材料的冲击强度,并利用SEM观察纳米复合材料的冲击断面形貌。实验结果表明,当OMMT的含量为4wt%时,纳米OMMT/EP复合材料的冲击强度比未掺杂纳米组分的EP提高了16.7%。经硅烷偶联剂处理后的CNTs(Si-CNTs)能与EP基体形成良好界面,当Si-CNTs的含量为0.9wt%时,纳米Si-CNTs/EP复合材料冲击强度比未掺杂纳米组分的EP提高了84.0%。当OMMT的含量为4wt%、Si-CNTs的含量为0.9wt%时,纳米Si-CNTs-OMMT/EP复合材料的冲击强度比未掺杂纳米组分的EP提高了135.4%。管状CNTs和片层结构OMMT对EP的韧性具有协同提高作用。 相似文献
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首先采用Hummers法制备出氧化石墨烯(GO),然后与三聚氰胺、甲醛进行原位聚合,制备出GO/密胺树脂(MF)复合材料,并用傅里叶红外光谱仪(FT-IR)、原子力显微镜(AFM)、扫描电镜(SEM)分析和观察了氧化石墨烯及复合材料的分子结构及形貌,通过导热系数测试仪、热重分析仪(TG)对复合材料的热性能进行了表征。研究发现,随着氧化石墨烯(GO)添加量的增加,复合材料导热系数增加先快后慢,当GO添加量为0.84%时,复合材料导热系数提高32.0%,GO的添加提高复合材料低温下的热稳定性。 相似文献