软体防刺复合材料的设计与优化

采用模压成型工艺制备了个体防护装备用软体防刺复合材料, 研究了树脂基体种类、 纤维织物种类和树脂含量对复合材料防刺性能的影响。结果表明, Surlyn树脂体系具有优异的防刺性能; 芳纶织物作为增强材料的复合材料穿刺性能优于UHMWPE织物; 树脂含量对复合材料的防刺性能也有影响, 当树脂的质量分数为47%时, Kevlar/Surlyn复合材料的防刺性能最优。     

软体防刺复合材料的设计与优化

采用模压成型工艺制备了个体防护装备用软体防刺复合材料,研究了树脂基体种类、纤维织物种类和树脂含量对复合材料防刺性能的影响.结果表明,Surlyn树脂体系具有优异的防刺性能;芳纶织物作为增强材料的复合材料穿刺性能优于UHMWPE织物;树脂含量对复合材料的防刺性能也有影响,当树脂的质量分数为47％时,Kevlar/Surlyn复合材料的防刺性能最优.     

乙烯基酯树脂/石墨双极板复合材料的制备EI北大核心CSCD

以天然鳞片石墨为导电骨料,乙烯基酯树脂为粘接剂,炭黑为添加剂,采用模压成型工艺制备了质子交换膜燃料电池双极板用乙烯基酯树脂/石墨复合材料。研究了树脂含量、成型工艺条件和炭黑含量对复合材料电导率和弯曲强度的影响,采用扫描电子显微镜、差示扫描量热法和热重分析等技术进行分析表征。实验结果表明:随着树脂含量的增加,材料的电导率下降,弯曲强度上升;施压温度对材料性能影响很明显;适当增大模压压力可有效改善材料的电导率和弯曲强度;成型温度和保温时间主要影响树脂的固化度;材料的电导率和弯曲强度随着炭黑含量增加均呈先增后减的趋势;在树脂质量分数为15%,施压温度为100℃,模压压力18 MPa,成型温度160℃,保温10 min,炭黑质量分数为10%的条件下,样品的电导率和弯曲强度分别可达85.7 S/cm和48.4 MPa。     

新型石墨基复合材料导电性能与力学性能影响因素的机理分析

以石墨与酚醛树脂粉料为原料通过低温热模压成形工艺制备新型石墨基复合材料.首先进行单因素试验分析了酚醛树脂含量、固化时间对复合材料导电性能与力学性能的影响机理;然后利用均匀试验方法进行多因素试验分析了酚醛树脂含量、固化温度、固化压力对复合材料导电性能与力学性能的综合影响.     

模压法制备C/C复合材料的研究

对模压法制备 Ｃ／ Ｃ复合材料的坯体模压工艺过程、 Ｃ／ Ｃ复合材料的致密化过程及 Ｃ／ Ｃ复合材料的结构和性能的相关性进行了研究。结果表明,物料中纤维含量及模压的温度、压力是影响初坯体成型及其密度的关键;除工艺条件外,原料的组成也是影响 Ｃ／ Ｃ复合材料致密化的重要因素;对 Ｃ／ Ｃ 复合材料力学性能研究的结果表明, Ｃ／ Ｃ复合材料的密度对材料的力学性能有很重要的影响。     

碳纤维增强酚醛树脂/石墨复合材料双极板的低温热模压试验研究

介绍了国外制备树脂/石墨复合材料双极板的研究结果.研究了低温热模压成型工艺制备酚醛树脂/石墨复合材料双极板,结果表明:酚醛树脂含量为15wt%时,复合材料的导电性能满足双极板的要求,但力学性能偏低.提出了碳纤维增强的解决方案,研究了碳纤维表面处理方法以及碳纤维含量对复合材料导电性能与力学性能的影响.得到对碳纤维进行液相氧化处理,碳纤维含量3wt%是综合性能较好的一种试验方案.采用低温热模压工艺制备低成本酚醛树脂/石墨复合材料双极板,双极板材料的性能突破必将促进燃料电池的商业化发展.     

燃料电池复合材料双极板的制备与性能研究

双极板是燃料电池中的重要组成部分,采用模压热固化二步法,以树脂为粘结剂、天然鳞片石墨作导电骨料、碳黑为添加剂制备燃料电池复合材料双极板.系统考察了树脂含量、溶剂比、碳黑含量、成型压力、保压时间以及固化温度等因素对复合材料双极板性能的影响.结果表明,随着粘结剂含量的增加,双极板的电导率减小,抗折强度增大;碳黑的添加可有效地提高其电导率,但强度会有一定程度的减小;增大成型压力和延长保压时间可提高双极板的导电性和强度;最终固化温度主要影响粘结的交联程度.制备天然石墨/聚合物复合材料双极板的最佳条件为:聚合物树脂含量为20%,碳黑含量为4%～5%,溶剂比为1.0,成型压力为10～12MPa,固化温度为180℃.     

制备工艺对SiCf/Si-O-C复合材料弯曲强度的影响

以聚硅氧烷为先驱体，采用先驱体转化法制备SiCf／Si-O-C复合材料。研究制备工艺参数模压压力、裂解时升温制度、裂解温度、保温时间对材料的力学性能的影响。通过对复合材料微观结构的分析研究，发现界面结构与致密度是影响SiCf／Si-O-C复合材料性能的主要因素。     

预氧丝毡复合材料的力学性能探讨

首次以预氧丝毡为增强材料,以环氧树脂为基体,采用模压成型工艺制备预氧丝毡复合材料。研究了预氧丝毡前处理方式、固化剂用量和固化压力对复合材料力学性能的影响,以复合材料纵、横向拉伸性能和弯曲性能为评价指标,优化出最佳的预氧丝毡复合材料制备方法,并利用扫描电子显微镜观察分析了复合材料的拉伸断面。结果表明,采用模压成型工艺制备的预氧丝毡复合材料具备良好的力学性能。经过前处理的预氧丝毡制备的复合材料板材力学性能优于未处理的板材。当固化剂用量为树脂质量的60%、固化压力为3 MPa,复合材料拉伸和弯曲性能最佳。     

短切石英纤维/ 聚酰亚胺复合材料的制备与性能

采用湿法混合工艺制备了短切石英纤维增强的PMR 型聚酰亚胺复合材料模塑粉, 使用热模压一次成型技术制备了聚酰亚胺树脂基复合材料, 对复合材料的性能进行了系统研究。研究结果表明: 短切石英纤维增强的复合材料具有优异的热性能和良好的力学性能, 纤维含量对复合材料玻璃化转变温度和热失重温度影响不大,对材料的力学性能影响显著。复合材料具有优异的介电性能, 在1 kHz～18 GHz 宽频范围内具有稳定的介电常数和介电损耗。      

用废纸与木片制备复合包装材料的热压工艺研究

热压温度与热压时间是热压工艺的主要参数,是影响废纸－木材复合材料物理力学性能的重要因素.为了获得较好的热压工艺条件,以杨木刨花为原料,废纸为补充原料,异氰酸酯改性的脲醛树脂为胶黏剂,生产了废纸－木材复合材料,并测试了热压温度与热压时间对废纸－木材复合材料物理力学性能的影响.试验结果表明：随着热压时间的延长,废纸－木材复合材料的物理力学性能相应地提高;在140～170 ℃的热压温度范围内,升高热压温度有助于提高废纸－木材复合材料的物理力学性能.废纸－木材复合材料较适宜的热压工艺条件为：热压时间为每mm板厚30 s,热压温度为170 ℃.     

石英纤维/聚酰亚胺复合材料的制备与性能

采用DSC、TG、FTIR和流变仪对KH-370聚酰亚胺树脂的化学反应特性和流变性能进行了表征。以QWB200石英纤维为增强体,采用热压成型工艺制备了QWB200/KH-370复合材料。研究了加压温度、压力大小、固化温度等不同工艺参数对QWB200/KH-370复合材料力学性能的影响,在此基础上确定了复合材料的成型工艺制度。考察了QWB200/KH-370复合材料400℃高温下的力学强度及宽频范围内的介电性能。结果表明,制备QWB200/KH-370复合材料的最佳工艺参数为:加压温度290~310℃,压力范围3.0~4.0 MPa,固化温度380℃。所得QWB200/KH-370复合材料具有良好的力学性能,400℃下力学强度保持率高于58%,表现出良好的耐热性能;而且在1~18 GHz的宽频范围内具有稳定的介电常数和介电损耗。      

FABRICATION OF METALLIC-GLASS RIBBON REINFORCED GLASS-CERAMIC MATRIX COMPOSITES

Metallic-glass ribbon reinforced glass-ceramic matrix composites were fabricated by conventional wet pressing and sintering techniques. Some of the important aspects of composite fabrication are discussed. Variables such as binder content, compaction pressure and specimen size, and their interdependency on one another are discussed. The optimum processing conditions required to obtain the best specimens are described. The sintering temperature was also found to be very important. The sintering temperature not only controls the softening characteristics of the parent glass, but also affects the specimen distortion. Proper selection of the sintering temperature can ensure minimum distortion in the specimens, while at the same time retain the ease and efficiency of fabrication.     

Preparation of C-fibre borosilicate glass composites: Influence of the fibre distribution on mechanical properties

Optimum conditions with respect to preparation-determined fibre distribution in borosilicate glass composites were investigated. Continuous C-fibre bundles were impregnated with glass powder in silicon alkoxide solution and wound in parallel to prepregs which were hot pressed into unidirectional composites. The influence of the glass particle size during the impregnation of fibre bundles and during hot pressing on the homogeneity of the fibre distribution was of special interest, as well as the influence of pressure and temperature on the densification of the composites. Optimum conditions were related to optimum values in the bending strength of the resulting composites. Under the optimum hot-pressing conditions the fibre volume content was varied. It has been shown that the fibre distribution was much more homogeneous when fine-grained glass powder was used for impregnation. At high fibre volume concentrations of the composites the distribution was better than at low concentrations. High fibre concentrations were connected with fracture toughness of the sample, as shown by the three-point bending experiments, whereas samples with low C-fibre concentration showed brittle behaviour.     

复合材料热压成型过程的树脂压力测试系统

在树脂基复合材料的成型工艺中大多涉及到树脂的流动过程, 而树脂压力是反映这一过程的重要参数, 监测成型过程中树脂压力的变化可以为工艺参数的选择和构件质量的控制提供指导。本文中针对热压工艺, 根据液体传压原理和特点, 自行研制了复合材料成型过程树脂压力测试系统, 对系统的精度和动态响应性能进行了研究, 并以该系统为测试手段, 初步研究了玻璃纤维单向层板中树脂压力的变化规律。结果表明, 该系统具有准确度高和动态响应敏感的特点, 满足热压成型过程树脂压力的测试要求, 为研究工艺过程树脂流动行为提供了有力的测试与验证手段。      

原位聚合碳纤维增强聚甲基丙烯酸甲酯基复合材料损伤与修复研究

基于热塑性复合材料易修复的特性,开展了碳纤维增强聚甲基丙烯酸甲酯(PMMA)基复合材料修复技术研究。研究了工艺温度、压力和时间对复合材料力学性能的影响规律。结果表明：在200℃、0.75 MPa压力下保持10 min可以获得优化的复合材料力学性能。引入低速冲击损伤,使用热压修复工艺修复碳纤维增强PMMA基复合材料的损伤。通过X射线断层扫描测试、超声波无损检测技术和断面摄像方法评估了此复合材料的损伤行为和修复效果。结果表明：低速冲击对碳纤维增强PMMA基复合材料的损伤分为低变形量区域的纵向开裂与分层和高变形量区域的纤维断裂与基体失效的混合模式。碳纤维增强PMMA基复合材料损伤试样经过热压修复后,损伤外形恢复良好,损伤区域大小显著减少,内部的开裂和分层等损伤恢复良好,复合材料压缩强度从140 MPa恢复至263 MPa,达到未损伤复合材料压缩性能(307 MPa)的85.7%。     

Effects of process parameters on properties of aluminium/stainless steel fibre metal matrix composites made by diffusion bonding

Abstract

A vacuum, high pressure diffusion bonding process was employed to manufacture aluminium/304 stainless steel fibre composites. The process parameters, including time, temperature, and pressure, were systematically changed to examine their effects on the tensile properties of composite. Pressure holding time ranged from 5 to 60 min. The hot pressing temperature was changed from 475 to 600°C and the selected pressures were 30, 70, and 100 MPa. It was found that the tensile properties only changed slightly with variation of hot pressing time and pressure. However, the tensile properties changed significantly with hot pressing temperature when the temperature was high enough such that an aluminium/stainless steel fibre interfacial compound was observed in the optical micrograph. The mechanism of change in the tensile properties was explained in terms of optical micrographs and SEM fractographs.     

Formulating the effects of applied temperature and pressure of hot pressing process on the mechanical properties of polypropylene–hydroxyapatite bio-composites by response surface methodology

Mechanical properties of polypropylene–hydroxyapatite (PP–HA) bio-composites produced by hot press molding depend on different parameters, particularly the pressure and temperature of the hot pressing process. In this study, a mathematical models for the effects of the pressure and temperature of the hot pressing process on the mechanical properties of the polypropylene–hydroxyapatite composites is developed using a response surface methodology. Ultimate tensile strength, Young’s modulus and impact absorbed energy were target parameters of the formulas and the temperature and pressure of the hot pressing process were independent input parameters. Formulas were derived by a nonlinear regression analysis and then were refined at the end. The validity of the formulas was also verified by experimental data. It was found that the obtained results by the formulas are matched closely to the experimental results; and the formulas have adequate precision in the ranges of the experimental data. The maximum error that occurs for the calculated results by the formulas is about 7%. The effectiveness of the pressure and temperature of hot pressing process on the mechanical properties of the composites was investigated using sensitivity analyses of the formulas. It was found that the sensitivity of the mechanical properties with respect to pressure of hot pressing process is more than temperature. Furthermore, the ultimate tensile strength of the composites has most sensitivity respect to the pressure and temperature of the hot pressing process than other mechanical properties.     

竹炭/酚醛树脂复合导电材料的制备与性能

以碳化温度为900 ℃的竹炭为导电骨料、 酚醛树脂为黏结剂、 炭黑为添加剂, 采用模压成型法制备竹炭/酚醛树脂复合导电材料。考察了竹炭的粒度、 酚醛树脂用量、 炭黑用量、 成型压力及固化温度等工艺因素对竹炭/酚醛树脂复合导电材料导电性和抗弯强度的影响。结果表明: 随着酚醛树脂用量的增加, 复合材料的抗弯强度增大, 电导率先增大后减小; 增加成型压力可同时提高复合材料的电导率和抗弯强度; 增大竹炭粉粒的粒径、 增加炭黑用量、 提高固化温度有利于改善复合材料的导电性, 但会不同程度地改变复合材料的力学性能。制备竹炭/酚醛树脂复合导电材料的最佳工艺条件为: 竹炭粒度≤75 μm, 树脂用量30%, 炭黑用量7.5%, 成型压力280 MPa, 固化温度180 ℃。