混杂纤维复合材料性能研究

对碳纤维织物、玻璃纤维织物和芳纶织物的性能进行测试,采用热熔法分别制备了一种增韧中温固化环氧碳纤维织物预浸料、玻璃纤维织物预浸料和芳纶织物预浸料。预浸料以单种预浸料铺层和不同纤维织物预浸料混合铺层方式铺贴组合,通过模压法成型复合材料层合板,进行性能测试并对比。结果表明,增韧中温固化环氧树脂的不同纤维织物预浸料混合铺层成型的层压板力学性能可以根据铺层设计优化,并不损失不同纤维铺层之间的界面性能。     

连续碳纤维增强聚醚醚酮复合材料的制备及力学性能

采用自主研发的连续碳纤维/聚醚醚酮热熔法预浸料(HC2110),通过热压成型工艺制备了复合材料层合板。测试了复合材料的力学性能,表征了微观形貌和破坏模式。预浸料热性能测试表明,HC2110预浸料较国外材料(TC1200)的耐热性及成型工艺性较优。微观形貌分析表明,复合材料层合板中纤维分布均匀性对0°拉伸性能影响较小;而纤维和树脂的界面结合较差是导致90°拉伸强度明显偏低的主要原因。     

国产高强高模PAN基碳纤维预浸料的制备及性能研究

以国产CNI QM55高强高模聚丙烯腈(PAN)基碳纤维、氰酸酯树脂为原料,利用热熔法制备高强高模PAN基碳纤维预浸料,通过纤维面密度、树脂含量、挥发分含量等来评价预浸料的物理性能,结合单向板的微观形貌与层间剪切强度分析单向板的界面结合性能,并对预浸料铺制单向板的力学性能进行表征。结果表明：CNI QM55碳纤维预浸料的纤维面密度为145 g/m²,树脂质量分数为35.5%,挥发分质量分数为0.164%,预浸料的物理性能满足复合材料的性能要求;以CNI QM55碳纤维预浸料制备的单向板0°拉伸强度为2 429 MPa, 0°拉伸模量为328.4 GPa,弯曲强度为1 171 MPa,弯曲模量为280 GPa,压缩强度为783 MPa,压缩模量为257 GPa,层间剪切强度为65.2 MPa,具有较好的界面黏接性能和力学性能,可满足加工应用要求。     

碳纤维复合材料厚壁管的成型工艺

本发明提供一种以碳纤维预浸料制作厚壁管的成型工艺,属于复合材料的成型工艺领域。本发明采用碳纤维预浸料进行剪裁、铺叠、卷管、缠带和固化,制成碳纤维复合材料厚壁管。本发明提供的成型工艺,使管件铺层设计不受限制,纤维在不同方向上的分布量可以精确控制,纤维角度可以设计。制备过程中不造成环境污染,成型后无需后期加工处理。制备的厚壁管质量轻、孔隙率低、纤维体积分数高、承载能力强。本工艺方法使用T700级碳纤维环氧型预浸料生产内经37 mm49 mm1 200 mm     

碳纤维/乙烯基树脂预浸料双真空袋成型工艺研究

本文使用乙烯基树脂预浸料以双真空袋成型工艺制备复合材料,研究了阶梯固化制度对制品力学性能及孔隙率的影响,当固化工艺为100℃/3 h+140℃/4 h,且在固化前期维持内层袋膜真空度为-0.075 MPa 2 h时,成型4 mm厚层合板力学性能最好,孔隙率最低为0.45%,成型10 mm厚层合板时,孔隙率为1.75%,也小于2%,证明了该工艺成型厚板的可行性。     

真空成型大型制品用碳纤维预浸料

正本发明公开的真空成型大型制品用碳纤维预浸料,其包括单向碳纤维预浸料层和片状或网状纤维基材层,单向碳纤维预浸料层一面被基体树脂完全浸透,另一面未被基体树脂完全浸透,其中片状或网状纤维基材层覆盖在单向碳纤维预浸料层没有被基体树脂完全浸透的一面上;片状或网状纤维基材层中的碳纤维为网状无序的碳纤维网片。本发明     

连续碳纤维增强聚苯硫醚预浸料层间滑移行为研究

层间滑移是热塑性复合材料零件热变形工艺的重要成型机制,对预浸料层间滑移行为的研究是热变形成型复合材料零件的褶皱缺陷预测和控制的基础。本文研究了连续碳纤维/聚苯硫醚预浸料热变形成型中的滑移行为,采用自行设计制作的测试系统,对缎纹织物预浸料、单向预浸料的滑移行为进行了表征,并考虑了温度、法向压力、速度对滑移行为的影响。结果表明提高试验温度、降低拉动速度和法向压力,都有利于纤维的运动,促进预浸料的层间滑移变形。采用Stribeck模型对连续碳纤维/聚苯硫醚预浸料的层间摩擦系数进行预测并与实验结果进行对比,结果表明赫西数与摩擦系数之间存在线性关系。     

超薄T700/环氧树脂预浸料力学性能研究及微观结构表征

为了研究超薄碳纤维树脂基预浸料力学性能并探究其微观结构,制备了常规和超薄预浸料层合板,对其进行了基础力学性能测试并利用金相显微镜、扫描电子显微镜及原子力显微镜表征了微观结构。通过对比发现,薄层化提高了复合材料宏观拉伸性能,降低了弯曲和层间剪切性能,但是薄层化后的复合材料在抵抗基体分层裂纹方面表现出了显著的优势;同时薄层化会使纤维在树脂中分布均匀,层间孔隙减少,纤维与树脂的界面厚度减小。     

风电叶片用国产碳纤维预浸料工艺性能和力学性能研究

应用碳纤维制备风电叶片结构件是大型风电叶片制作技术的一个发展方向。为推动国产碳纤维的发展应用,给出了风电叶片对碳纤维预浸料的技术要求,研究了国产碳纤维预浸料和进口碳纤维预浸料的力学性能和工艺性能,通过对比分析发现,面密度低的国产碳纤维预浸料力学性能高于进口碳纤维预浸料,但面密度≥600g/m2的国内碳纤维预浸料的工艺性能较差,需要进一步改进。     

碳纤维外壳的制造方法

正本发明公开了一种碳纤维外壳的制造方法,包括步骤:将单向碳纤维预浸料叠层排布形成内层和中间层,中间层上的单向碳纤维预浸料与内层上的单向碳纤维预浸料呈0°的夹角;将碳纤维平纹布预浸料铺设在中间层上形成外层;内层、中间层和外层形成预成型原料;将预成型原料放入模具中并按预设的成型条件固化成型,形     

Properties of carbon fiber composite laminates fabricated by coresin film infusion process for different prepreg materials

A new cocured process called coresin film infusion (co‐RFI) process, which combines RFI process and prepreg/autoclave process, was introduced and four kinds of commercial carbon fiber prepreg material systems and a kind of resin film were applied to fabricate co‐RFI laminates. The compatibility between the resin film and the prepreg matrix and the application of co‐RFI process were investigated based on the resin flowability, glass transition temperature of cured resin, processing quality of laminate, and variation in resin modulus on cocured interphase region measured by nanoindentation. Furthermore, mode I (G_IC), mode II (G_IIC) delamination fracture toughness, and flexural strength and modulus were measured to evaluate the mechanical properties of cocured laminates with different prepreg materials. The experimental results show that thickness and fiber volume fraction of co‐RFI laminates with the four kinds of prepreg materials are similar to those of prepreg laminates and RFI laminate with acceptable differences. In addition, there are no obvious defects in co‐RFI laminates. Moreover, the reduced modulus of resin at cocured interface and glass transition temperature values of the mixed resin reflect good compatibility between prepreg matrix resin and RFI resin. The G_IC, G_IIC values, and flexural performances of cocured laminates lie between and even exceed those of prepreg laminates and RFI laminates, indicating no weakening effect in the cocured interface. Therefore, the co‐RFI process is believed to effectively fabricate composite with low cost and it can be applied using various prepreg systems. POLYM. COMPOS., 34:2008–2018, 2013. © 2013 Society of Plastics Engineers     

Fabrication and mechanical response of commingled GF/PET composites

The mechanical properties and the response to mechanical load of continuous glass fiber reinforced polyethylene terephthalate (GF/PET) laminates have been characterized. The laminates were manufactured by compression molding stacks of novel woven and warp knitted fabrics produced from commingled yarns. The laminate quality was examined by means of optical and scanning electron microscopy. Few voids were found and the laminate quality was good. Resin pockets occurred in the woven laminates, originating from the architecture of the woven fabric. The strength of the fiber/matrix interface was poor. Some problems were encountered while manufacturing the laminates. These led to fiber misalignment and consequently resulted in tensile mechanical properties that were slightly lower than expected. Flexural failures all initiated as a result of compression, and it is possible that the compression strength of the matrix material, rather than its tensile strength, might limit the ultimate mechanical performance of the composites. Flexural failures for both materials were very gradual. The warp knitted laminates were stronger and stiffer than the woven laminates. The impact behavior was also investigated; the woven laminates exhibited superior damage tolerance compared with the warp knitted laminates.     

The Influence of Temperature and Pressure During the Curing of Prepreg Carbon Fiber Epoxy Resin

The physical and hence mechanical properties of carbon fiber reinforced epoxy resin are affected by the curing conditions used in their manufacture. The relationship between the cure temperature and pressure and the density, fiber volume fraction, and the void content of cured laminates, was investigated. For the unidirectional 914C prepreg material used, an optimum cure temperature was found which gave maximum fiber volume fraction and composite density, and minimum void content. This behavior is related in the paper to resin flow and cure characteristics. A linear relationship between cure pressure and fiber volume fraction is reported and explained by reference to the void content of the laminates. It is concluded that in-house trials are required to determine the optimum size of the processing window for specific systems and components.     

Room-temperature aging of Narmco 5208 carbon-epoxy prepreg. Part II: Physical,mechanical, and nondestructive characterization

Samples of Narmco Rigidite 5208/WC3000 carbon-epoxy composite prepreg were exposed to ambient temperature (22°C) and 50 percent relative humidity for different periods up to 66 days. The aging has a significant effect on prepreg physical properties such as tack, volatiles content, and gel time. A set of 4-ply laminates made from aged prepreg was subjected to tensile testing, ultrasonic inspection, and optothermal inspection. No relationship could be discerned between laminate properties and prepreg aging time. However, variations in panel homogeneity were observed, and these correlated with thermal diffusivity and tensile modulus measurements, but not with ultimate tensile strength or elongation. A set of 6-ply laminates was used to measure compressive properties, interlaminar shear strength, and physical properties. These panels also showed variations in porosity, again unrelated to aging, but in addition, the fiber/resin ratio was observed to decrease with aging time. Both factors were found to affect mechanical properties. The implications concerning the importance of monitoring the aging by physicochemical methods are discussed.     

化学气相渗透2.5维C/SiC复合材料的拉伸性能

采用等温减压化学气相浸渗(isothermal low-pressure chemical vapor infiltration,ILCVI)工艺制备了在厚度方向上具有纤维增强的2.5维(2.5 dimensional,2.5D)碳纤维增强碳化硅多层陶瓷基复合材料,从而使一端封口的防热结构部件的制备成为可能.ILCVI致密化后,复合材料的密度、孔隙率分别为1.95～2.1 g/cm3和16.5%～18%.沿经纱和纬纱两个方向对2.5D C/SiC复合材料进行室温拉伸实验.结果表明:复合材料在纵向和横向的拉伸应力-应变均表现为明显的非线性行为.复合材料具有较高的面内拉伸性能,纵横向的拉伸强度分别为326MPa和145MPa,断裂应变分别为0.697%和0.705%.复合材料的拉伸断裂为典型的韧性断裂,经纱和纬纱的断裂都表现为纤维的多级台阶式断裂以及纤维的大量拔出.     

非热压罐预浸料制备及成型工艺研究

采用单面胶膜浸渍的方法制备非热压罐(Out of Autoclave,以下简称"OoA")预浸料。采用三种方法测定预浸料的浸渍度,通过预浸料的细观形貌、层压板孔隙率及力学性能,系统地分析了浸渍度对碳纤维增强复合材料(CFRP)质量的影响,22%的浸渍度时性能最优。与OoA预浸料相匹配的固化工艺至关重要,通过无损检测、孔隙率、微观结构及力学性能对比分析,120℃/2 h作为第一阶段的固化工艺最适合,同时层压板热性能、力学性能与热压罐相媲美。     

Self-adhesive honeycomb prepreg systems for secondary structural applications

Porosity in cured honeycomb parts was investigated using model prepreg systems and compared with a commercial solvent produced prepreg. Woven glass fabric was used as the reinforcement in both of the systems. Three main solvents were identified in the commercial prepreg. These solvents were found to cause porosity or reduce thermal properties in model solvent prepreg based laminates when used either separately or in combination. Lowering the solvent content reduced the porosity in the prepreg but was limited by resin staging. The high level of porosity, resulting from solvents, found in these commercial prepreg systems motivated the investigation of the feasibility of changing the method of impregnation from solvent to hot-melt. Hot-melt model prepreg produced essentially void-free laminates as well as honeycomb parts. Model prepreg produced by hot-melt impregnation was found to be more robust, providing the capability of changing the degree of resin impregnation in the fiber bed. A low level of impregnation resulted in the best fillets to the honeycomb core, while still producing essentially void free parts. The use of both solid and liquid carboxyl-functional elastomers was incorporated in the epoxy based resin to provide flow control and self-adhesive characteristics. Mechanical properties of both the model hot-melt and commercial prepreg based honeycomb structures and laminates were compared. The model hot-melt prepreg was found to have better cured properties along with the necessary prepreg characteristics providing an optimized self-adhesive controlled flow prepreg system.     

不同液态污渍在棉织物上的扩散成形规律及侵入动力学特征

为了揭示水溶性和油溶性污渍在棉织物上的扩散成形规律和动力学特性等一系列问题,解释液态污渍在织物上的形成机理,利用扫描电镜观察、毛细表征、接触角变化和高速摄像系统,记录相同体积下不同属性的污渍液滴在棉织物上侵入扩散动力学特征.结果表明:棉织物吸附能力较强,污渍扩散以纤维间扩散为主;当织物经密大于纬密时,污渍斑经向扩散直径...     

Structural degradation and mechanical fracture of hybrid fabric reinforced composites

This investigation involves the study of accelerated environmental aging in two polymer composite laminates reinforced by hybrid fabrics based on carbon, Kevlar and glass fibers. Composite laminate configurations are defined as a laminate reinforced with E‐glass fiber and Kevlar 49 fiber hybrid fabric (GK) and another laminate reinforced with E‐glass fiber and AS4 carbon fiber hybrid fabric (GC). Both laminates were impregnated with epoxy vinyl ester thermosetting resin (Derakane 470‐300) consisting of four layers. Morphological studies (photo‐oxidation process and structural degradation) of environmental aging were conducted, in addition to comparative studies of the mechanical properties and fracture characteristics under the action of uniaxial tensile and three‐point bending tests in specimens in the original and aged conditions. With respect to uniaxial tensile tests for both laminates, good mechanical performance and little final damage (small loss of properties) was caused by the aging effect. However, for the three‐point bending tests, for both laminates, the influence of aging was slightly higher for all parameters studied. The low structural deterioration in the laminates is attributed to the high performance with the heat of the matrix (Derakane 470‐300) and the characteristics of the hybrid fabric, exhibiting fiber/matrix interface quality. POLYM. ENG. SCI., 56:657–668, 2016. © 2016 Society of Plastics Engineers     

Mechanical Properties of Carbon Epoxy Prepreg Insert Phenolic Resin Injection Moldings

This study focuses on the insert-injection molding process. The thermoset composite inserts in this study were carbon fiber/epoxy(CF/Epoxy) prepreg sheets. The injected molded part was glass fiber contained phenolic resin(GF/PF). The CF/Epoxy was placed in the mold cavity prior to injecting GF/PF onto the inserted injection molded CF/Epoxy specimens. The role of adhesion between the inserted part and injected resin on the mechanical properties was evaluated by 3 point bending and impact tests. In addition, the effect of prepreg orientation on the mechanical properties of the prepreg inserted-injection molding system was investigated. It was found that the prepreg with unidirectional orientation significantly improved flexural and impact strength of the inserted injection molding composites, providing better support and resistance to bending and impact loading. The main failure modes of the specimens were structural and adhesive failure.