聚乳酸/玄武岩纤维复合材料的制备及性能研究

利用混杂原理,先将玄武岩纤维与聚乳酸纤维混合制成针刺毡,再与聚乳酸树脂复合,以提高树脂基体对增强体结构的渗透和结合性能。采用正交试验法,以混杂针刺毡中聚乳酸纤维含量、复合层压压力、复合层压温度为影响因素,讨论了混杂复合层压工艺对复合材料力学性能的影响。结果表明,采用混杂复合工艺有利于复合材料力学性能的改善,且混杂纤维含量在一定范围内时,复合材料的力学性能会随着混杂纤维含量的增加而线性增强,同时复合层压压力的增加也有利于复合材料力学性能的改善;采用混杂复合工艺时,复合层压温度对复合材料力学性能的影响规律不同于传统层压复合时复合层压温度对复合材料力学性能的影响,复合层压温度过高不利于复合材料力学性能的提高。     

针刺工艺对玄武岩针刺非织造复合材料性能的影响

以玄武岩针刺非织造织物为增强体,以硼酚醛树脂为基体树脂,采用层压复合工艺制备了复合材料,研究了不同针刺工艺对复合材料力学性能的影响。结果表明,相同针刺工艺条件下,复合材料的拉伸强度随复合层压压力的增加先增大后减小,复合材料的弯曲强度随复合层压压力的增加而线性增强;在一定情况下,增强体的孔隙率对复合材料力学性能的影响高于增强体拉伸强度对复合材料力学性能的影响。     

PA纤维／环氧树脂超混杂复合材料的层压成型工艺

本文研究了ＰＡ纤维／环氧基体超混杂复合材料的层压工艺，确定了超混杂复合材料的铺层叠合及工艺条件，在此工艺条件下制备的复合材料具有优异的性能。     

高模碳纤维M40/聚酰亚胺预成型膜层合复合材料的研究

采用膜层压方法,制备了单向高模碳纤维增强共聚聚酰亚胺复合材料;考察了共聚聚酰亚胺结构、纤维表面处理和成型工艺对复合材料性能的影响.结果表明膜层压复合材料的孔隙小,力学性能高,分子链柔顺的聚酰亚胺复合材料的力学性能高;纤维表面处理对复合材料的层间剪切强度影响不大;成型温度对复合材料的力学性能有显著的影响.     

苎麻纤维/玻璃纤维混杂增强不饱和聚酯复合材料的力学性能研究

采用真空辅助成型技术(VARI)制备不饱和聚酯为基体的苎麻/玻璃纤维混杂增强复合材料。通过改变层间混杂的铺层方式以及改变两种纤维的相对含量对比其力学性能,从而得到以上两种因素对力学性能的影响方式。结果表明,在相同的混杂比下,层间夹芯混杂(玻璃纤维在壳层,苎麻纤维在芯层)铺层的力学性能优于层间夹芯混杂(玻璃纤维在芯层,苎麻纤维在壳层)铺层,而层间交替混杂铺层的力学性能介于两者之间;在相同的铺层方式下,苎麻纤维相对含量与复合材料力学性能存在负相关关系,其中与拉伸性能呈现线性(一次函数)关系,与弯曲性能呈现三次函数关系。     

石墨烯复合UHMWPE纤维增强UHMWPE层压板的制备及性能

以超高相对分子质量聚乙烯(UHMWPE)为基体,石墨烯复合UHMWPE纤维织物为补强材料,采用优化层压工艺制备石墨烯复合纤维增强UHMWPE层压板,研究了石墨烯复合UHMWPE纤维用量对UHMWPE层压板拉伸、弯曲、热稳定性能的影响规律.结果表明:石墨烯复合UHMWPE纤维可显著增强UHMWPE层压板的力学性能,也可略...     

树脂基PEMG超混杂复合材料层压成型工艺研究

研究了树脂基聚乙烯纤维/金属纤维/玻璃布(PEMG)超混杂复合材料层压成型工艺及其性能。结果表明,PEMG超混杂复合板不仅具有良好的力学性能,而且兼有耐腐蚀、耐磨损性能,具有较大的推广应用价值。     

长纤混杂增强复合材料注塑成型的微观结构演化

采用熔体浸渍拉挤工艺(LFT-G)制备长碳纤/玻纤混杂增强聚丙烯(LCF/LGF/PP)复合材料。首先研究了纤维表面处理、微观形貌、界面结合状态对复合材料力学性能的影响,并研究了纤维不同混配比对复合材料力学性能的影响。结果表明,纤维经表面处理,增加了与基体的机械啮合作用,改善了界面结合形貌,提高了复合材料的力学性能。与单一纤维增强复合材料相比,混杂增强纤维更易形成随机取向的三维骨架结构。且碳纤和玻纤混合质量比为2∶1时,其注塑制品获得相对较高的强度、韧性和刚度,同时具有相对较低的成本。     

基体的韧化对复合材料力学性能温度依赖性的影响

前言随着液体羧基丁腈橡胶增韧环氧树脂研究工作的深入,基体的韧化对复合材料性能的影响引起了人们的关注。众所周知,基体树脂的力学性能有明显的温度依赖性,当然可予想,复合材科的力学性能也体现出树脂的影响。而基体对复合材料力学性能温度依赖性的影响,与复合材料的纤维/基体界面胶接强度的温度依赖性有关。尤其,由于基体的热性质不同,对各个温度下复合材料破坏方式的影响,会造成复合材料力学性能温度依赖性的变化。本文使用未韧化与无规羧基丁腈橡胶和双酚A韧化的两类热性质不同的环氧树脂基体,进行复合材料力学性能温度依赖性的探讨,以便进一步了解韧化基体对复合材料力学性能的影响。     

混杂方式对CF/UHMWPEF混杂复合材料力学性能的影响

本文通过碳纤维/超高分子量聚乙烯纤维混杂复合材料的力学性能试验及结果比较,分析了三种混杂方式对该类复合材料的力学性能的影响.结果表明,不同混杂方式的碳纤维/超高分子量聚乙烯纤维复合材料具有各自的力学特点.     

针刺碳纤维增强莫来石基复合材料的制备及性能

采用溶胶-凝胶法制备了针刺碳纤维增强莫来石基复合材料。借助于TG-DTA和XRD对合成凝胶的莫来石化过程进行研究,结果表明,在热处理过程中,凝胶在920°C左右形成铝硅尖晶石,1198°C左右形成莫来石。研究了烧结温度对复合材料性能的影响,结果表明,烧结温度为1500°C制备的复合材料弯曲强度最高,达到142.2 MPa,断裂韧性为8.77 MPa·m~(1/2)。借助于对复合材料微观结构的观察对复合材料力学性能的变化进行了解释。     

Effects of fiber contents on the mechanical and microwave absorbent properties of carbon fiber felt reinforced geopolymer composites

In this paper, phosphate-based geopolymer composites are studied and the effects of different carbon fiber felt contents (from 20?vol% to 40?vol%) on the phase composition, microstructure, mechanical properties and microwave absorbent properties from 2?GHz to 18?GHz frequency band of the composites were systematically investigated. The results indicate that with the increase in carbon fiber felt contents, flexural strength and Young's modulus of the composites gradually increased. The fracture mode of the composite changed from brittle failure to ductile failure with the presence of carbon fiber felt. It was mainly due to the micropore deformation as well as fibers pulling-out and the crack deflection, which consumed most fracture energy. However, microwave absorbent performance tended to increase at first and then decreased as the carbon fiber felt content ramping up. When the content of carbon fiber felt in the composite was 26.7?vol%, the composite showed the best microwave absorbent performance and the reflection loss reached to ??59.3?dB. It is mainly attributed to the Debye polarization of the carbon fibers and the interface polarization between fibers and the matrix.     

三维针刺C/SiC复合材料无纬布纤维方向对材料力学性能的影响

通过化学气相渗透法结合反应熔体浸渗法制备了三维针刺C/SiC复合材料,采用扫描电子显微镜观察材料的显微结构,并研究了无纬布纤维方向对材料力学性能的影响.结果表明,三维针刺C/SiC复合材料由O°无纬布层、短纤维胎网层、90°无纬布层以及针刺纤维束组成,无纬布层纤维方向对材料性能有显著影响.试样的拉伸强度和弯曲强度随着无纬布纤维方向与试样长度方向的夹角θ(0 ～45°)值的增大而减小,面内剪切强度和冲击韧性随θ角的增大而增大.     

Mechanical properties of glass fiber/organic fiber mixed–mat reinforced thermoplastic composites

The purpose of this study is to investigate the influence of different types of fibers on the mechanical properties of hybrid composite materials. Long and short glass fibers (GF) and different types of organic fibers, viz. aramid fiber, DuPont Kevlar‐49 (KF), liquid crystalline polymer (LCP), and vinylon (VF) in hybrid composites, were used to reinforced the high density polyethylene (HDPE) matrix. The long fiber hybrid composites were prepared in a “fiber separating and flying machine,” while the short fiber hybrid composites were prepared in an “elastic extruder.” The total amount of fibers used in both long and short fiber hybrid composites was fixed at 20 vol%. The influence of fiber content, length, and mixing ratio on mechanical properties, such as tensile, bending, Izod and high rate impact strength, as well as viscoelastic propertics in the solid state, was studied. Fracture surfaces of the materials were also examined using a scanning electron microscopy.     

热处理对EP/CF及EP/CF/GF复合材料力学性能的影响

采用真空辅助树脂转移模塑（VARTM）技术制备了环氧树脂/碳纤维（EP/CF）和环氧树脂/碳纤维/玻璃纤维毡（EP/CF/GF）复合材料。测试了两种纤维铺层方式中树脂流动距离的平方与流动时间的关系,对两种铺层纤维体系的渗透率进行了研究对比;将两种复合材料进行高温处理,并且对其高温处理前后的力学性能进行分析;利用扫描电子显微镜（SEM）观察了复合材料的拉伸断口形貌。结果表明,EP/CF/GF中GF毡的松散结构使树脂更易流动;高温热处理造成了EP/CF弹性模量和拉伸应变的降低,其中弹性模量降低了9.97 %、拉伸应变降低了11.36 %,但对EP/CF/GF的影响较小;GF毡的加入造成了2种复合材料弯曲性能的下降;未经处理的复合材料断口表面光滑,而热处理后的复合材料断口表面粗糙且有大量基体附着。     

Ablation of the carbon/carbon composite nozzle-throats in a small solid rocket motor

Ablation of needled carbon/carbon (C/C) composite nozzle-throats was studied by hot-fire testing in a small solid rocket motor. The composition of the combustion gases was estimated by principle of free energy minimum. The ablation morphology was investigated by scanning electron microscopy. The ablation mechanism of C/C composites was also studied. The results showed that the ablation performance of C/C composites was determined by mechanical breakage of fibers/matrix together with thermal chemical ablation from the heterogeneous reactions on the throat surface. The mechanical breakage of fibers/matrix dominated the ablation of the composites at high pressure based on the calculated ablation rate. Cone-shaped fibers were formed after ablation in high fiber density area; but in low fiber density area, the fibers were peeled off because of the weakened strength after ablation. Meanwhile, the matrix around the fiber bundles was ablated into a shell shape, while the matrix between the cone-shaped fibers might be blown away by the combustion gases. Oxidation of C/C composites led to the formation of the cone-shaped fibers and shell-shaped matrix, as well as the loss of matrix between the cone-shaped fibers. The fiber/matrix fragments on the ablation surface were caused by the mechanical breakage.     

以环己烷为前驱体制备炭/炭复合材料

以环己烷为前驱体利用化学液气相沉积工艺,采用针刺炭纤维毡为预制体,制备了具有光滑层和粗糙层结构的炭/炭复合材料。利用金相显微镜、高分辨扫描电子显微镜进行了材料的微观组织结构的分析,分析了在不同位置不同织构热解炭的形成机理。同时阐述了化学液气相沉积工艺原理。实验结果表明,通过调整工艺参数,利用化学液气相沉积工艺可以制备具有不同微观组织结构的炭/炭复合材料。     

芳纶1414纤维含量对针刺毡性能的影响

研究芳纶1414纤维含量对芳纶针刺毡性能的影响,在相同面密度和相同针刺密度的条件下,生产不同质量比的芳纶1313与芳纶1414针刺毡,测试了不同质量比的芳纶针刺毡的力学性能和阻燃性能。结果表明:随着芳纶1414纤维含量的增加,针刺毡试样的断裂强力、撕破强力及顶破强力先减小后增大,断裂伸长呈振荡式变化,且其各项燃烧性能指标逐步提高。