Environmental Simulation Experiments of 3D-C/SiC Composites with Different PyC Interfacial Layers

A series of 3D-C/SiC composites with different pyrolytic carbon (PyC) interracial layers (about 20～300 nm thick)were prepared by chemical vapor infiltration.     

金属基复合材料界面残余应力的研究进展

综述了金属基复合材料界面残余应力的各种影响因素、残余应力的实验测试方法和理论分析方法及残余应力对复合材料宏观力学性能的影响,分析讨论了目前研究中存在的问题和不足之处,并指出了今后工作的重点与方向.     

Interfacial Micromechanics of Hybrid Metal Matrix Composites

Hybrid metal matrix composites (MMCs) in which adjoining matrices have different plastic responses have potential to offer more attractive damage tolerance properties than conventional MMCs \[1]. At the interface of two dissimilar metal matrices, both capable of deforming plastically, the accentuated free-edge stresses may cause intermatrix decohesion to form an interface crack. In this article, the solution of a local-global analysis to determine the mechanics environment governing onset of such intermatrix debonding is presented. First an effective method of asymptotic local analysis for the singular interfacial stress in plastically deforming hybrid MMCs \[1-5] is summarized and new results are presented. Then, the generalized stress intensity factor that scales the free-edge interfacial stresses is solved by a global analysis for several illustrative cases. The global analysis is performed via elastic-plastic finite-element method. The solutions presented completely characterize the dominant mechanical environment that governs the onset of intermatrix decohesion. The solutions, with proper interpretation, are also applicable to hybrid MMCs at elevated temperatures with matrices deforming by power-law creep. \[6]     

Interfacial Effects on Stress Transfer in Fiber-Reinforced Composites

A three-dimensional solution for a fiber-reinforced circular cylinder is presented for axisymmetric force and displacement boundary conditions. The solution, which can satisfy all the boundary conditions prescribed on the curved and end surfaces of the cylinder, can be used directly in the micromechanical analysis of fiber-reinforced composites to investigate the typical representative volume element (RVE). The element consists of a combined circular cylinder composed of a solid inner circular cylinder of transversely isotropic fiber, a concentric outer circular cylinder of isotropic matrix material, and an interface layer between the fiber and the matrix. The radial and tangential flexural compliances of the interfacial material are considered, and their effects on the stress transfer at the interface are studied parametrically. The numerical results presented show that the material properties of the interfacial layer have significant influences on the stress distribution within the RVE, particularly at the cross sections near the ends of the cylinder, where external loads are applied.     

木塑复合材料界面改性方法研究进展

自1983年美国生产了第1批木塑复合材料(WPCs)以来,作为一种最具潜力的复合材料,木塑复合材料在建筑和结构应用方面都引起了人们极大的兴趣,其应用不仅可以减小环境污染,而且还可以缓解石油危机。热塑性树脂和植物纤维之间相容性的差异直接影响了木塑复合材料综合性能的提高。文中概述了木塑复合材料界面处理方法的最新研究进展,并对其超/亚临界流体处理方法的优缺点进行了分析和探讨。     

天然植物纤维复合材料界面改性研究进展

天然植物纤维基复合材料性能优异,但天然植物纤维独特的结构性能,致使其与聚合物复合还存在诸多问题。提高天然植物纤维在聚合物基体中的分散性,增加纤维与聚合物基体的相容性对于提高天然植物纤维复合材料力学性能有着至关重要的作用。概述了天然植物纤维及其复合材料制备在界面改性方面的研究进展,总结了纤维改性对复合材料性能的影响,目前天然植物纤维改性处理的方法主要有热处理法、碱处理法、偶联剂法、酰化法、表面接枝法、复合处理法等。随着天然植物纤维改性研究的不断深入,天然植物纤维基复合材料应用前景将更加广阔。     

An Investigation of Interfacial Fatigue in Fiber Reinforced Composites

Based on the shear-lag model and the modified degradation formula for coefficient of friction, the interfacial fatigue and debonding for fiber reinforced composites under cyclic loading are studied. The loading condition is chosen as the kind that is the most frequently used in fiber-pull-out experiments. The stress components in the debonded and bonded regions are obtained according to the maximum and minimum applied loading. By the aid of theory of fracture mechanics and Paris formula, the governing equation is solved numerically and the interfacial debonding is simulated. The relationships between the parameters (such as the debond rate, debond length, debond force) and the number of cycles are obtained.     

有机太阳能电池阴极界面层概述

体相异质结聚合物太阳能电池因具有质轻、柔韧性好、便于大面积印刷等优点引起了越来越多的关注。近年来,聚合物太阳能电池取得了较大的进步。然而,聚合物太阳能电池要实现商业化大面积制备还需要解决一些科学问题,如电荷的分离、传输和收集效率低等。良好的界面接触对提高器件性能至关重要。本文综述了聚合物太阳能电池界面层的作用及分类,包括无机类、富勒烯类、水/醇溶性中性共轭聚合物、水/醇溶性离子型共轭聚合物电解质、超支化小分子和苝酰亚胺衍生物。     

乙烯基酯复合材料/橡胶界面性能研究

通过对橡胶表面进行处理并涂刷柔性过渡层,研究橡胶与乙烯基树脂复合材料的界面粘接性能。结果表明,橡胶表面经过化学处理后,出现大量细小微裂纹,使得橡胶与乙烯基酯复合材料的界面粘接强度得到大幅度提高;在经过化学处理后的橡胶表面涂刷柔性能渡层,二者界面剥离强度提高到2.90 k N/m,粘合强度达到2.30 MPa。     

树脂基复合材料界面及界面表征

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。     

碳纤维增强铝复合材料的界面微观结构

利用透射电镜（TEM）对超声浸渗制备的碳纤维（T300及M40J）增强铝复合丝及液矸渗法制备的碳纤维增强铝复合板材的界面微观结构进行了分析,结果表明,超声浸渗法制备的复合丝有明显的界面反应产物,T300／Al的反应程度比M40J／A1高。液相压渗法制备的复合材料界面反应不明显,表明该工艺可避免不利的界面反应发生。     

Analysis of Interfacial Coating Effect on Thermal Stress in Composites

A preliminary model for the analysis of thermo-mechanical behaviour of interfacial coatings on thefibers in unidirectional composites have been developed on the solution of thermo-elastic mechan-ics. Thermal stress would be introduced into the composite during cooling because of the mismatchof thermo-mechanical properties among their components. The low modulus coating can effectivelyreduce the interracial stress caused by different thermal expansion coefficient between fibers and ma-trix, no matter how high or low the expansion coefficients of coatings are in CF/Al and SiC/Ticomposite systems, however, high modulus coating can decrease the interfacial compressive stress,only when the thermal expansion coefficient of coating is lower.     

Interfacial Elastic Fields of Nano- and Microcrystalline Inclusions in Composites

A model was proposed for low-angle boundaries of nano- and microcrystalline inclusions in composites. The model, describing low-angle boundaries as an ensemble of rectangular dislocation loops, was used to calculate the stress field of rectangular dislocation loops, necessary for determining the characteristics of nanocrystalline inclusions in elastic isotropic composites. The elastic energy of the low-angle boundaries of an isolated nanocrystallite and a cluster of nanocrystallites was evaluated as a function of the misorientation parameters of the boundaries.     

颗粒增强铝基复合材料界面性能的研究

颗粒增强铝基复合材料具有较好的比刚度、比强度、抗疲劳、耐热耐磨和辐射屏蔽等优点,广泛应用于航空航天、军工、电子和汽车等领域。在这类材料中,基体-增强体界面的结构与性能对复合材料宏观性能影响显著。综述了颗粒增强铝基复合材料主要的制备方法和应用现状,特别聚焦于界面的结构及其对复合材料宏观性能的影响方式与机制,同时指出了复合材料制备过程中各种因素对材料界面性质的影响。最后,展望了颗粒增强铝基复合材料界面性能研究的发展前景,指出可采用先进的微纳米尺度的测量技术,结合显微结构表征的方法,系统地研究界面性能与结构之间的关系。     

Interfacial Shear Strength Measurements of SiC Fiber-Reinforced Titanium Composites

A continuous loading push-out test technique was used to measure the interfacial shear strength of SiC fiber reinforced Ti matrix composites. The interracial shear strength of samples as-fabricated and after heat exposed at 700 and 800℃ for 50 h was successfully determined. It has been found that the interfacial shear strength of the specimen exposed at 700℃ was higher than that of as-prepared and exposed samples at 800℃. The shear strength of the as-prepared samples was about 112.45 MPa, and increased to about 153.77 MPa after heat-treating at 700℃ for 50 h, but decreased to 133.11 MPa after treating at 800℃ for 50 h. Scanning electron microscope (SEM) was used to investigate the interfacial morphology of the samples. The brittle phase was the main products of interface for samples exposed at 800℃, and the interface was easily peeled off.     

石英纤维增强含硅芳炔树脂复合材料的界面增强

制备苯乙炔全封端的含硅芳炔树脂,与含硅芳炔树脂(PSA)共混,得到满足RTM成型工艺要求的低黏度含硅芳炔树脂,合成三乙氧基乙炔基硅烷(TEOAS)并应用于改性石英纤维(QF)布,采用RTM工艺制备石英纤维增强的PSA树脂复合材料。对共混树脂的加工工艺性、耐热性能、石英纤维的表面和复合材料的性能进行研究。结果表明:共混PSA树脂不但具备较高的耐热性,而且有良好的加工工艺性能;X射线光电子能谱(XPS)分析表明QF表面接枝上乙炔基,TEOAS处理后QF与共混PSA树脂的界面黏结强度增强,复合材料的弯曲强度和层间剪切强度(ILSS)分别较未处理时提高了28.8%和25.4%。     

Interfacial Interaction in Coated Carbon Fibre Reinforced Aluminous Mg-based Composites

Four kinds of Mg alloys reinforced with carbon fibres were fabricated by a gas pressure infiltration technique. The fibres were pre-coated a SiO2 layer prior to fabrication. DifFerent microstructures and interactions in the fibre-matrix interface of these composites were observed by transmission electron microscopy （TEM）. The results showed that the interracial interaction strongly depended on the content of Al in the Mg-based matrices. The microstructure of the interface could then be controlled by adjusting the Al content of the Mgbased matrix. In addition, fibres extracted from different Mg-based matrix all had some degradation owing to the interracial reaction and the fibre-matrix interdiffusion.     

橡胶夹层/复合材料粘接界面疲劳裂纹扩展行为的研究

用 型加载下的双悬臂夹层梁试样 ,以应变能释放率为裂纹扩展参量 ,研究橡胶夹层 /复合材料粘接界面疲劳裂纹的扩展行为。结果表明 ,循环载荷下的裂纹扩展速率对试验频率、载荷比、温度及橡胶夹层厚度反映较敏感。     

原位法表征碳／碳复合材料界面性能的研究

用单丝顶出和束顶出法分别测试了细编穿刺碳／碳（Ｃ／Ｃ）复合材料不同层次的界面粘结性能，研究了生产工艺对不同层次界面性能的影响，建立了顶出试验的力学模型，并用有限元方法分析了界面上应力的分布情况，对可能的界面破坏模式进行了预测，为最终优化Ｃ／Ｃ复合材料的生产工艺提供了依据。     

ABS/PET复合材料的制备及界面相容性

采用醇化聚对苯二甲酸乙二醇酯(PETG)和乙烯-正丁基丙烯酸酯-甲基丙烯酸缩水甘油酯共聚物(PTW)对聚对苯二甲酸乙二醇酯(PET)进行改性,再与丙烯腈-苯乙烯-丁二烯共聚物树脂(ABS)制成复合材料。扫描电镜(SEM)表明,改性后的PET相在ABS基体中分散均匀,形成的分散相区尺寸小,相容性好。红外光谱分析发现,界面经冷热循环后,PET分子中乙二醇链段从左右式构象转变为反式构象,当复合材料在经受高低温试验的过程中,PET和ABS因具有不同膨胀系数而在界面处产生应力。采用改性PET可使ABS/PET复合材料的拉伸强度、弯曲强度和缺口冲击强度分别提高10.8%、13.3%和150%。