Comparison of Tensile Properties of Carbon Fiber,Basalt Fiber and Hybrid Fiber Reinforced Composites Under Various Strain Rates

Applied Composite Materials - Carbon fiber reinforced epoxy (CFRE) and basalt fiber reinforced epoxy (BFRE) are used widely in automotive, navy due to their excellent mechanical performance. In...     

玻纤增强聚丙烯复合材料的应变率敏感特性

采用层合热压实验法将玻璃纤维基毡与聚丙烯薄膜复合制成不同玻纤含量的玻纤增强聚丙烯(GF/PP)复合板材,在不同的加载速率下进行拉伸测试,研究GF/PP复合材料的应变率敏感特性,分析Burgers模型对该材料本构关系拟合预测的可行性。结果表明:GF/PP复合材料在低应变率范围内对应变率是敏感的,随应变率的增加,其断裂应力和抗拉强度增大;随玻璃纤维含量的增加,其所对应的应变率效应反而有所下降。同时,Burgers模型能够有效地拟合预测出该材料的拉伸应力-应变曲线,与实验曲线相比,进一步验证了GF/PP复合材料的应变率敏感特性及其变化趋势。     

碳纤维表面结构对复合材料吸湿性能的影响

通过改变阳极氧化处理程度得到了具有不同表面结构的碳纤维, 然后将其与环氧树脂加工成碳纤维/树脂基复合材料, 研究了碳纤维的化学结构与湿热环境下复合材料吸湿之间的关系。结果显示: 阳极氧化处理后碳纤维表面的活性显著提高, 碳纤维表面含氧官能团的含量大幅增加, 尤其是-OH由处理前18.62%提高到处理后的34.84%。随着湿热处理条件的改变, 复合材料的吸湿机理也有所差异, 且温度是影响复合材料吸湿的重要因素。碳纤维表面活性越高, 复合材料达到吸湿平衡时的平衡吸湿量越大, 而平衡吸湿量的增加又会导致复合材料层间剪切强度(ILSS)下降幅度增大。     

碳纤维增强热塑性聚酰亚胺及其复合材料

采用双螺杆共混挤出法,在热塑性聚酰亚胺(TPI)树脂中添加碳纤维(CF)进行复合增强,实验研究了碳纤维种类、加入量及成型方法对复合材料力学性能的影响.结果表明:碳纤维的加入能显著提高材料的常温和高温力学强度,并与碳纤维种类有关;复合材料的拉伸和弯曲强度均随着碳纤维加入量的增大而升高;相对于模压成型方法,注塑成型可获得更高强度的复合材料.由扫描电镜(SEM)观察到的材料拉伸和弯曲断面的微结构形貌,初步探讨了碳纤维的增强机理.     

碳纤维增强羟基磷灰石/环氧树脂复合材料的制备与力学性能

采用树脂传递模塑(RTM)工艺制备了碳纤维增强环氧树脂以及碳纤维增强羟基磷灰石(HA)/环氧树脂两种复合材料，并测试了其力学性能。结果表明，RTM工艺可以基本保证环氧基体均匀浸入碳纤维织物内部。碳纤维增强HA，环氧复合材料的冲击韧性高于碳纤维增强环氧复合材料，而弯曲强度和弯曲模量低于碳纤维增强环氧复合材料。两种复合材料的弯曲强度远高于人体皮质骨，弯曲模量与皮质骨非常接近。动态力学分析(DMA)表明加入HA后，复合材料的贮存模量和内耗降低，玻璃化转变温度升高。     

碳纤维水泥基材料的电热效应

研究了碳纤维水泥基材料(CFRC)的电热效应,包括最大温升与外加功率的关系、升温规律和降温规律等。结果表明:CFRC材料的最大温升与其外加功率满足良好的线性关系;其升温曲线和降温曲线可由特定的表达式来描述,且外加功率越大,升温速率越大。这一研究对碳纤维水泥基材料在海工工程上的应用具有重要意义。     

Thermo-physical Properties of Continuous Carbon Fiber Reinforced Copper Matrix Composites

Continuous carbon fiber reinforced copper matrix composites with 70％(volume fraction)of carbon fibers prepared by squeeze casting technique have been used for investigation of the coefficient of thermal expansion(CTE)and thermal conductivity．Thermo-physical properties have been measured in both, longitudinal and transversal directions to the fiber orientation．The results showed that Cf／Cu composites may be a suitable candidate for heat sinks because of its good thermo-physical properties e．g．the low CTE(4.18×10-6／K)in longitudinal orientation and(14．98×10-6／K)in transversal orientation at the range of 20-50℃，a good thermal conductivity(87．2 W／m·K)in longitudinal orientation and(58．2 W／m·K)in transversal orientation．Measured CTE and thermal conductivity values are compared with those predicted by several well-known models．Eshelby model gave better results for prediction of the CTE and thermal conductivity of the unidirectional composites．     

Experimental Study on Tensile Behavior of Carbon Fiber and Carbon Fiber Reinforced Aluminum at Different Strain Rate

In this study, dynamic and quasi-static tensile behaviors of carbon fiber and unidirectional carbon fiber reinforced aluminum composite have been investigated. The complete stress–strain curves of fiber bundles and the composite at different strain rates were obtained. The experimental results show that carbon fiber is a strain rate insensitive material, but the tensile strength and critical strain of the C_f/Al composite increased with increasing of strain rate because of the strain rate strengthening effect of aluminum matrix. Based on experimental results, a fiber bundles model has been combined with Weibull strength distribution function to establish a one-dimensional damage constitutive equation for the C_f/Al composite.     

织布形状对玄武岩纤维布/不饱和聚酯树脂复合材料力学性能的影响

对玄武岩纤维布增强不饱和聚酯复合材料的基本力学性能进行了初步研究,针对纤维织布方式不同,制备了3种不同的复合板,即平纹复合板、斜纹复合板和平纹/斜纹复合板。结果表明,在相同层数17层和19层的条件下,斜纹复合板的拉伸、弯曲和无缺口冲击强度明显高于平纹和平纹/斜纹复合板。平纹/斜纹复合板强度较差,分散性大,而平纹复合板分散性小,物理力学性能稳定。     

C/C复合材料压缩破坏的应变率效应研究

研究了碳布叠层/碳复合材料在四种不同应变率下的压缩性能, 对其在准静态、动态载荷下的压缩破坏机理进行了初步的探讨. 研究结果表明: C/C复合材料的压缩破坏强度具有较强的应变率效应, 与准静态(10^-4/s)相比, 复合材料的动态(1.5×10²/s)压缩强度可提高70%左右; 复合材料在准静态、动态载荷下力学性能的差异可归结为纤维与基体界面特性的应变率效应以及不同应变率下破坏模式的不同.     

冷等离子处理对炭纤维表面及复合材料性能的影响

空气气氛下对T300炭纤维进行不同时间的等离子处理。对处理后的炭纤维表面进行了扫描电镜(SEM)观察,对表面活性基团进行了红外光谱测试。结果显示,随着处理时间的增长,纤维表面沟槽长度加长,程度加深,表面粗糙度增大。纤维表面并没有明显的活性基团产生。将处理后的炭纤维制备成单向增强板,测得试样的弯曲模量达到109GPa;弯曲强度在处理时间为16min之内增加较快达到1241.5MPa,超过16min之后开始下降。等离子处理前后的力学性能相比,弯曲模量提高了50.97%,弯曲强度提高了46.89%。实验结果显示,等离子处理16min能够得到比较好的界面结合性能和力学性能。     

Preparation of Metal-Coated Carbon Fiber Reinforced Composites and Their Electromagnetic Properties

Medium temperature curing by infrared radiation was used to prepare electromagnetic wave absorbing multilayered plastic matrix composite materials containing metal-coated carbon fibers (MCFs). The electromagnetic properties of the materials were investigated by frequency scanning tests with microwave vector network analyzer. It is found that the electromagnetic parameters, mainly permittivity of the composites increase significantly with the addition of MCFs, which gives the composites good designability as thin, light-weight EM wave absorbers. It is also shown that MCFs can improve on the EM wave energy attenuating property of the composites by widening the work frequency band width and raising the absorptive peak     

碳纤维织物增强聚苯硫醚复合材料的制备及性能

采用薄膜叠压法制备碳纤维织物增强聚苯硫醚(CFF/PPS)复合材料层压板,研究了热压温度、热压压力和热压时间对复合材料层压板力学性能的影响,确定了制备CFF/PPS复合材料的理想工艺参数为:热压温度320～330℃,热压压力0.15～0.20MPa,热压时间8～10min。在该参数下制得的层压板拉伸强度为652MPa,弯曲强度为711MPa,层间剪切强度为43MPa;在6.7J/mm的冲击能量下,层压板的冲击后压缩剩余强度为116MPa。     

UHMWPE纤维/碳纤维混杂复合材料性能研究

用层内及层间混杂方式制备了超高相对分子质量聚乙烯(UHMWPE)纤维/碳纤维混杂复合材料,对复合材料的力学性能、动态力学性能(DMA)及微观形貌(SEM)进行了分析比较.结果表明,层内混杂复合材料的综合性能好于层间混杂复合材料,层内混杂复合材料的冲击强度在UHMWPE纤维相对于碳纤维质量分数为43%时有最大值423.3kJ/m2,层内混杂复合材料的贮能模量(E')、损耗因子(tanδ)和损耗模量(E')明显地向高温方向移动,混杂复合材料的玻璃化温度(Tg)及模量分别比UHMWPE复合材料提高了2倍和3倍.     

碳纤维水泥基复合材料Seebeck效应研究现状

具有显著Seebeck效应的碳纤维水泥基复合材料(Carbon fiber reinforced cement-based composites,简写为CFRC)近年来受到广泛关注。综述了CFRC的导电机理、Seebeck效应强化途径及其工程应用前景。CFRC的载流子类型主要包括离子、电子和空穴,并以空穴为主。碳纤维/碳纳米管掺杂,CFRC的Seebeck系数可提高至约30μV/℃;钢纤维掺杂水泥基材料表现为n型半导体,其Seebeck可达68μV/℃;金属氧化物Bi_2O_3掺杂可将CFRC的Seebeck系数稳步提高到100.28μV/℃,而ZnO和Fe_2O_3掺杂可使CFRC的Seebeck系数分别增大到3 300μV/℃和2 500μV/℃。这些研究有效地促进了CFRC在城市室外热量的转换收集、工业余热能量收集和长寿命结构健康监测传感器等领域的研究与发展。     

复合材料用玄武岩增强纤维的性能研究

对玄武岩纤维结构与成分进行了介绍,对其力学性能、耐久性能、阻燃性能和耐温性能进行了研究。结果表明:玄武岩纤维性能因其原料产地不同而有较大差异,复杂的化学组成是决定其性能的根本原因。通过与其他高性能纤维对比,玄武岩纤维具有优异的力学性能、耐湿热老化性、阻燃性能、耐温性能,能够很好的应用于复合材料中。     

碳纤维增强共聚酰胺6-66复合材料的制备及性能

通过两段式聚合法制备共聚酰胺PA6-66,然后采用熔融共混得到碳纤维增强PA6-66复合材料(CF/PA6-66).对复合材料的断面形貌、热性能、结晶性能、非等温结晶动力学、熔体流变性、力学性能和动态力学性能进行了分析.差示扫描量热(DSC)和热重分析结果表明,CF/PA6-66复合材料的熔点约为190℃,分解温度在3...     

Anisotropic Dielectric Properties of Carbon Fiber Reinforced Polymer Composites during Microwave Curing

Microwave cuing technology is a promising alternative to conventional autoclave curing technology in high efficient and energy saving processing of polymer composites. Dielectric properties of composites are key parameters related to the energy conversion efficiency during the microwave curing process. However, existing methods of dielectric measurement cannot be applied to the microwave curing process. This paper presented an offline test method to solve this problem. Firstly, a kinetics model of the polymer composites under microwave curing was established based on differential scanning calorimetry to describe the whole curing process. Then several specially designed samples of different feature cure degrees were prepared and used to reflect the dielectric properties of the composite during microwave curing. It was demonstrated to be a feasible plan for both test accuracy and efficiency through extensive experimental research. Based on this method, the anisotropic complex permittivity of a carbon fiber/epoxy composite during microwave curing was accurately determined. Statistical results indicated that both the dielectric constant and dielectric loss of the composite increased at the initial curing stage, peaked at the maximum reaction rate point and decreased finally during the microwave curing process. Corresponding mechanism has also been systematically investigated in this work.     

炭纤维针刺预制体增强C/SiC复合材料的制备与性能研究

以炭纤维复合网胎针刺织物为预制体, 采用“化学气相渗透法+先驱体浸渍裂解法”(CVI+PIP)混合工艺, 制备了C/SiC陶瓷复合材料; 研究了针刺预制体的致密化效率以及复合材料的微观结构和力学性能, 并与目前常用的三维编织C/SiC复合材料和预氧丝针刺织物增强C/SiC复合材料进行了对比. 结果表明, 针刺预制体的致密化效率明显高于三维编织预制体, 在相同致密工艺条件下, 炭纤维针刺织物增强复合材料和预氧丝针刺织物增强复合材料的密度分 别达到2.08和2.02g/cm³, 而三维编织预制体增强复合材料的密度仅为1.81g/cm³. 炭纤维针刺复合材料的力学性能高于预氧丝针刺复合材料, 弯曲强度和剪切强度分别达到237和26MPa.