金属间化合物/陶瓷基复合材料的制备工艺与研究进展

金属间化合物材料具有许多优良的性能,可以将金属间化合物与陶瓷材料相复合形成金属间化合物/陶瓷基复合材料.金属间化合物/陶瓷基复合材料是近年来发展起来的一种新型复合材料,制备的金属间化合物/陶瓷基复合材料具有很多优异的性能.本文主要介绍金属间化合物/陶瓷基复合材料的制备工艺和力学性能以及研究进展,研究和开发的金属间化合物/陶瓷基复合材料主要包括Fe-Al金属间化合物/陶瓷复合材料,Ti-Al金属间化合物/陶瓷复合材料和Ni-Al金属间化合物/陶瓷复合材料.本文对金属间化合物/陶瓷基复合材料未来的发展趋势进行了分析和预测.     

装甲防护材料的新葩——陶瓷-金属功能梯度复合材料

本文重点说明了在陶瓷增强的金属基复合材料的基础上，发展起来的陶瓷增强颗粒连续分布的陶瓷-金属功能梯度复合材料用作防护装甲的优点，介绍了陶瓷-金属功能梯度复合装甲材料的研究现状，并对其未来发展做了阐述。     

偶联剂处理陶瓷颗粒增强聚丙烯复合材料的性能

用熔融共混法制备了陶瓷颗粒增强聚丙烯复合材料,测试了复合材料的力学性能,探讨了研究了表面处理对PP复合材料性能的影响。结果表明:偶联剂处理陶瓷颗粒表面后,复合材料的拉伸强度和冲击强度均比未处理的有所提高。拉伸断面的扫描电镜照片分析表明,未活化处理陶瓷颗粒与PP的界面粘结较差,界面发现许多空隙;而偶联剂KH-550活化处理后,陶瓷颗粒能与PP界面粘结良好,在拉伸过程中多数陶瓷颗粒被基体牢固粘附而难以脱出。     

可加工陶瓷研究进展

介绍了国内外可加工玻璃陶瓷、石墨系复相陶瓷、h-BN系纳米复相陶瓷、可加工层状复相陶瓷、可加工多孔陶瓷、稀土磷酸盐系复相陶瓷和Mn＋1AX。化合物等7种可加工陶瓷的制备机理的研究现状,并对该领域今后的发展方向进行了进一步探讨。     

Overview of Fine-Scale Piezoelectric Ceramic/Polymer Composite Processing

In the past two decades, piezoelectric ceramic/polymer composites with different connectivities have been developed for transducer applications such as hydrophones, biomedical imaging, nondestructive testing, and air imaging. Recently, much attention has been given to fine-scale piezoelectric ceramic/polymer composites. These composites allow higher operating frequencies, and thus increased resolution, in medical imaging transducers. In this review, methods for processing fine-scale piezoelectric ceramic/polymer composites are discussed. The current capabilities, strengths, and weaknesses of each method are compared. The importance of spatial scale in composite performance is also reviewed. Several of the processing methods have demonstrated composites with fine-scale ceramic phases (<50 μm), and others have potential to form composites with a ceramic scale of under 20 μm.     

三维编织压电陶瓷基复合材料有效电弹性性能有限元分析

基于三维编织预制件的细观结构,建立了三维编织压电陶瓷基复合材料位移-电耦合场有限元模型,利用电弹性场体积平均思想和有限元方法研究了周期分布三维编织压电陶瓷基复合材料的有效电弹性性能。通过对代表性体积单元施加位移载荷和电载荷边界条件,预测了不同纤维体积分数下三维编织压电陶瓷基复合材料的有效弹性常数、压电常数和介电常数。计算结果表明,三维编织压电陶瓷基复合材料可显著改善压电陶瓷的整体力学性能,且保持了较好的电学性能。     

超高温陶瓷材料研究进展

超高温陶瓷材料以其优异的综合性能有望成为新一代高温热防护材料.目前超高温陶瓷材料主要分为烧结超高温陶瓷材料和连续纤维增强超高温陶瓷基复合材料,将对烧结超高温陶瓷材料的研究进展做重点介绍,随后简要介绍连续纤维增强超高温陶瓷基复合材料的优势和研究概况.     

Environmentally-harmless polylactic acid-polyethylene glycol binder for deformable ceramic green body

We report a polylactic acid (PLA)-polyethylene glycol (PEG) mixture as a thermoplastic binder to prepare shape-machinable ceramic green bodies. During the mixing process, the high viscosity of the PLA binder impedes effective mixing with ceramic powders. To address this issue, PEG was introduced as a plasticizer into ceramic/PLA composites to diminish the overall viscosity of the feedstock, which resulted in effective mixing with ceramic powders. After sintering green bodies composed of PLA-PEG binders and ceramic compounds, the mechanical properties (flexural strength and porosity) of the sintered specimens were investigated and compared with those of sintered specimens made from wax-based green bodies. The sintered specimens made from ceramic/PLA-PEG composites showed comparable mechanical properties and porosities with the sintered specimens made from ceramic/wax composites. In addition, the shape-machinable characteristic of the green bodies made from ceramic/PLA-PEG composites was demonstrated by deforming the entire structure of the green bodies via simple heat treatment.     

Preparation of interpenetrating alumina–copper composites

To prepare interpenetrating alumina–copper composites, alumina foams were activated with titanium coating by chemical vapor deposition and then were infiltrated with molten copper by expendable casting process. The microstructure and phase composition of the composites were analyzed, and bending strength, electrical conductivity, friction and wear properties were tested. The results showed that the bonding between ceramic and metal was fine in the composites while no reactions took place between them because of the undissolved titanium coating. With increase of ceramic fraction, the electrical conductivity of the composite decreased, whereas the bending strength increased. The composite failure occurred by ductile fracture of the metal followed by fracture of the ceramic. The wear rate of the composites decreased with increase of ceramic fraction. And the wear of the composites was featured with ceramic struts peeling compared with ploughing and adhering wear for pure copper.     

Mixed connectivity composite material characterization for electroactive sensors

Electroactive composites consisting of a ferroelectric ceramic in a polymer matrix have gained much interest as compliant electromechanical or pyroelectric sensors. Of the various theoretical models developed to understand the dielectric and electroactive properties of composites, the majority are based on a cube of unit dimensions representing the matrix with fractional inclusions representing the ceramic. Composite properties are dictated by the choice of constituent materials along with the intra- and inter-connectivity of the separate phases. A ceramic powder randomly dispersed in a polymer matrix is referred to as having 0-3 connectivity, i.e. the ceramic phase possesses no intra-connectivity throughout the composite in the x, y, and z directions, whereas the polymer possesses full intraconnectivity in these directions. For thin composite films, where the ceramic grain size is comparable to the film thickness, or for composites with high ceramic volume content, the degree of ceramic connectivity throughout the composite thickness will be enhanced over thick or low ceramic content composites, thus implying an amount of 1-3 connectivity within the composite. In order to investigate the properties of such composites, a cube model has been applied that deals with mixed 0-3 and 1-3 connectivity composites. This paper reports on the experimental and theoretical characterization of two different mixed connectivity composites, one with a polar polymer matrix and another with a nonpolar matrix.     

Erosion behaviour of B4C-based ceramic composites

In this paper, TiO₂ was introduced into boron carbide and B₄C-based ceramic composites were obtained by uniaxial hot pressing. The mechanical properties, relative density and erosion behaviour of B₄C-based ceramic composites were investigated. X-ray analysis showed that the fabricated composites were composed of B₄C, TiB₂ and C phases. SEM technique was employed to observe the original polished surfaces and the eroded surfaces of B₄C-based ceramic composites. The effect of impingement angle, impact velocity of SiC erodent particle, relative density and phase ratio on the erosion rate of B₄C-based ceramic composites was determined. It was found that the erosion rate of B₄C-based ceramic composites increased with increasing of impingement angle and erodent particle velocity. The relative density and phase ratio influenced the erosion rate of B₄C-based ceramic composites significantly by influencing their mechanical properties.     

新型炭／陶复合材料电热性能研究

实验选取高岭土作为陶瓷基体,以不同含量的鳞片石墨和碳化硅作为导电原料,充分利用炭材料优异的导电、导热性及耐高温性能和陶瓷材料优异的抗氧化性及机械强度,经混合、模压成型和烧结工艺制备出炭／陶复合电热材料。采用XRD和SEM对其物相组成和微观形貌进行分析表征,并对其通电发热性能以及抗氧化性能等进行了测试。研究了石墨以及碳化硅的含量对复合材料电热性能的影响,并对电热机理进行了初步的分析研究。本研究所制备的炭／陶复合材料具有优异的电热性能,在低电压下（10V）即可迅速升温,并在较高温度下保持相对稳定。研制的样品中最高发热温度可达631℃。通过将炭材料和陶瓷材料复合,可有效改善炭材料的抗氧化性,使其氧化失重温度升高200℃左右。     

电子陶瓷和器件的低温共烧技术

较系统地介绍了电子器件用低温共烧陶瓷(low temperature cofired ceramics,LTCCs)材料,探讨了其工艺中的若干问题。电子器件用低温共烧陶瓷材料包括:玻璃/陶瓷复合材料、结晶化玻璃、晶化玻璃/陶瓷复合材料以及液相烧结陶瓷,其中典型的和最为常用的LTCCs为玻璃/陶瓷(特别是氧化铝)复合材料。正在研究的一些陶瓷介质材料中,Bi基介质材料引起了人们的关注。玻璃/陶瓷复合材料的制备工艺中,应当着重关注和加深了解玻璃的流动性和结晶性、玻璃的起泡、玻璃和陶瓷颗粒间的反应、共烧材料的匹配等问题,从优选材料配方和优化工艺着手,从而获得优质可靠的材质和器件。     

B4C--SiC/C复合材料氧化过程的TG/DTA分析

制备了Ｂ_４Ｃ－ＳｉＣ／Ｃ复合材料,对不同组成的复合材料在２０１５００℃升温氧化过程进行了ＴＧ／ＤＴＡ（热重和差热联用）分析。结果表明,复合材料具有不同的高温抗氧化性能,此差异可归因于以下几方面：复合材料的组成不同（包括陶瓷粒子的种类、含量）,不同种类的陶瓷粒子氧化转变成陶瓷氧化物的温度、速率不同,生成的陶瓷氧化物在高温下的物性（对基体材料的润湿性、粘度及流动性、挥发性和对氧的扩散系数等）不同。通过在炭基体中弥散Ｂ４Ｃ粒子可明显提高炭基体在８５０℃以下的抗氧化性。当复合材料中Ｂ４Ｃ含量较高而ＳｉＣ含量低时,样品表面将趋于形成Ｂ２Ｏ３较为富集的硼硅酸玻璃相,在１５００℃以下具有良好的氧化防护效果;当样品中ＳｉＣ含量较高时,在高温下（＞１２００℃）,随着部分Ｂ２Ｏ３的挥发和大量ＳｉＯ２的生成,样品表面将趋于形成ＳｉＯ２较为富集的硼硅酸盐玻璃相,在高达１４００℃以上仍具有良好的氧化防护效果     

Research and application prospect of short carbon fiber reinforced ceramic composites

With the advantage of high temperature resistance, low expansion, low density and excellent thermal stability, carbon fiber reinforced ceramic composites have a very wide range of applications in aerospace, military, energy, chemical industries and transportation. Short carbon fiber reinforced ceramic composites are characterized by simple processes, low manufacturing costs, short preparation times and automated production, can be used in fields such as friction materials and thermal protection system. This paper reviews the current status and recent advances in research on homogenization techniques, mechanical properties, thermal properties and frictional properties of short carbon fiber reinforce ceramic composites. Different processing routes for short carbon fiber reinforced ceramic composites, including reactive melt infiltration (RMI), hot pressing (HP), spark plasma sintering (SPS) and pressureless sintering, the advantages and drawbacks of each method are briefly discussed. The future development direction of low-cost manufacturing short carbon fiber reinforced ceramic composites is prospected.     

A model for 0‐3 piezoelectric composites with an interlayer

Based on the model for 0‐3 piezoelectric composites without an interlayer, a modified model for 0‐3 piezoelectric composites with an interlayer has been proposed and the expressions for this model consequently have been derived. The interlayer is supposed to act as a bridge between the ceramic and polymer matrix during the poling process. The calculated results show that the electric field strength on ceramic phase is influenced by the volume fraction of interlayer and ceramic in the composite, and dielectric constants of interlayer, ceramic, and polymer matrix. The electric field strength on ceramic phase increases with the interlayer volume fraction and dielectric constant ratio of interlayer and polymer matrix. This indicates that the ceramic polarization and piezoelectric performance of 0‐3 piezoelectric composites can be improved by design of the interlayer with appropriate dielectric constants and volume fractions into the 0‐3 piezoelectric composites. POLYM. COMPOS., 31:1922–1927, 2010. © 2010 Society of Plastics Engineers.     

层状复合陶瓷制备技术与界面特性

本文综合评述了层状复合陶瓷研究现状，分析了层状复合陶瓷的制备工艺和界面结合情况以及界对对层状复合陶瓷性能的影响。     

常温固化免烧结泡沫陶瓷复合材料的制备及性能

利用自制的粘结剂,选用合适的填料、悬浮剂和减水剂,表面活性剂等附加剂,采用聚氨酯泡沫塑料先驱体挂浆成形法和常温固化工艺,制备出具有均匀、相互贯通孔结构的免烧结泡沫陶瓷复合材料,其生产工序简单,生产成本低,同时由于聚氨酯泡沫塑料载体保留其中,所以产品韧性好,不易脆断,研究结果表明：随着粘结剂加入量的提高和泡沫塑料载体孔径的减小,泡沫陶瓷复合材料的抗压强度显著增大,但通孔率明显降低es用适当浓度的碱液对泡沫塑料进行表面改性处理,可显著降低其表面张力,提高表面粗糙度,还能溶解残留的封孔薄膜,从增加挂浆量,提高其力学性能,但随着泡沫塑料载体表面改性处理时间的延长,泡沫陶瓷复合材料的通孔率下降bde着常温固化时间的延长,泡沫陶瓷复合材料的抗压强度逐步上升,常温固化28d时,其抗压强度基本上达到最大值。     

Temperature-dependent fracture strength of whisker-reinforced ceramic composites: Modeling and factor analysis

In this study, a temperature-dependent fracture strength model for whisker-reinforced ceramic composites was developed. This model considers the strength degradation of both whisker and ceramic matrix at elevated temperatures, as well as the evolution of residual thermal stress with temperature. It was verified by comparison with the available flexural strengths of five types of whisker-reinforced ceramic composites at different temperatures, and good agreement between the model predictions and the experimental data is obtained. Moreover, based on the established model, we systematically analyzed the effects of six influencing factors, including the volume fraction and the aspect ratio of whisker, the Young's modulus of matrix and whisker, the thermal expansion coefficient difference and the stress-free temperature, on the temperature-dependent flexural strengths of whisker-reinforced ceramic composites. Some new insights which could help optimize and improve the temperature-dependent fracture strength of whisker-reinforced ceramic composites are obtained.     

复合陶瓷的应用发展是未来新材料市场的主题

陶瓷基复合材料不是传统意义上的陶瓷,它是以陶瓷为基体与各种纤维复合的一类复合材料。其主要基体有玻璃陶瓷、氧化铝、氮化硅等,具有高温强度好、高耐磨性、高耐腐蚀性、低膨胀系数、隔热性好及低密度等特性,而且资源也比较丰富,有广泛的应用前景。针对陶瓷基复合材料成为争夺国际市场的制高点,分析了陶瓷基复合材料的研发受到重视,阐述了复合陶瓷材料的特点,介绍了陶瓷基复合材料的应用领域,同时指出了节能环保的车用陶瓷基结构复合材料大有作为。