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层状复合是一种新型陶瓷增韧构型。本文着重讨论了层状复合陶瓷断裂特性,包括几种主要的增韧机制的分析和影响因素的讨论。 相似文献
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纳米氧化锆复合陶瓷由于具有良好的相变增韧性能而被作为新型义齿材料。本文介绍了被广泛应用于牙科界的两种纳米氧化锆复合陶瓷及其制备方法:纳米增韧复合陶瓷(ZTA)、四方相氧化锆多晶体(TZP),以及纳米氧化锆复合陶瓷的增韧机理与机制;概述了氧化锆复合陶瓷在牙科的研究现状以及氧化锆复合陶瓷材料的发展前景及应用限制。 相似文献
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《中国材料进展》2016,(12)
碳纳米管作为一维纳米材料,不仅重量轻,还具有强度高、韧性高等优异的力学性能,与工程结构陶瓷材料复合能够强韧化陶瓷材料的力学性能,被认为是现代结构陶瓷复合材料的理想增强体。在综合了近年碳纳米管增强陶瓷基复合材料的理论及实验方面研究结果的基础上,侧重介绍了碳纳米管增强陶瓷基复合材料的强韧化机理,如细化晶粒增韧、短纤维增韧、碳纳米管独特的坍塌增韧、多壁碳纳米管抽出增韧机制,并讨论了采用剪切滞后理论模型对碳纳米管与陶瓷基体的微观界面结合力学性能模拟的研究结果。分析了国内外碳纳米管在陶瓷基体中强韧化机理的实验及模拟研究结果,总结了当前碳纳米管增强陶瓷复合材料的研究困境与存在的问题,并指出了今后理论和实验研究的方向。 相似文献
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常压烧结ZTM/Al2O3复合陶瓷的力学性能 总被引:3,自引:0,他引:3
采用干法成型、常压烧结工艺制得致密的ZTM/Al2O3复合陶瓷材料。通过引入大颗粒的氧化铝,使ZTM陶瓷(氧化锆增韧莫来石陶瓷)的力学性能有明显提高。组成20Vol.%Al2O3-20Vol.%ZrO2-mullite陶瓷材料,其断裂韧性为6.06MPa·m^1/2,抗弯强度为403MPa。实验结果表明:Al2O3的弥散强化和ZrO2的相变增韧及微裂纹增韧是ZTM/Al2O3陶瓷的主要增韧机理。 相似文献
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碳化硅陶瓷以其优异的性能被广泛利用于各种领域,但其脆性限制了其性能的发挥,因此其增韧技术得到广泛研究并取得良好效果。综合评述了碳化硅陶瓷增韧机理和增韧方法的研究进展,包括晶须或纤维增韧、颗粒弥散增韧、表面改性技术增韧、自增韧、层状结构复合增韧的增韧机理和方法进。 相似文献
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层状陶瓷复合材料可有效提高纯陶瓷材料的韧性,受到研究者的广泛关注。在材料设计阶段,通过优化叠层方式可显著提高层状陶瓷的力学性能。然而,在现有研究中缺乏叠层方式的优化设计方法。本研究采用基于复合梁模型的遗传算法得到了最优层厚比;针对SiC-BN层状陶瓷复合材料5∶ 1、10∶ 1和梯度体三种铺层形式采用流延成型结合无压烧结法进行材料制备,并进行了完好试件和含缺口试件的三点弯曲试验;基于宏观损伤分析对其增韧机制进行了分析。试验结果表明:通过解析方法计算得到的最优梯度体层状陶瓷的弯曲强度达到434.5 MPa。其力学性能相比于固定层厚比铺层方式有较大提高,同时还保持了较高的缺陷不敏感特性。进一步分析表明:受拉部分分布的较多软层和受压部分分布的较厚硬层是梯度体结构较好性能的重要原因。 相似文献
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采用流延-化学气相渗透(TC-CVI)工艺制备SiC晶须(SiC_W)/SiC层状陶瓷复合材料,研究了SiC_W含量对层状陶瓷复合材料力学性能和微观结构的影响,探讨了SiC_W/SiC层状陶瓷复合材料的强韧化机制。结果表明:TC-CVI工艺能够有效提高复合材料中晶须含量(40vol%),减少制备过程对晶须损伤,所制备的SiC_W/SiC层状陶瓷复合材料具有合适的层内及层间界面结合强度。随着SiC_W含量增加,层状陶瓷复合材料的密度和力学性能均有明显提高。含40vol%晶须的SiC_W/SiC层状陶瓷复合材料的密度、弯曲强度和断裂韧性均比含25vol%晶须的分别提高了8.4%、30.8%和26.7%。断口形貌中能够观察到层间及层内的裂纹偏转,层内的裂纹桥接和晶须拔出等,这些为主要的增韧机制。高含量SiC_W及合适的层间和层内界面结合强度,对提高SiC_W/SiC层状陶瓷复合材料强韧性有明显作用。 相似文献
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A. Kelly 《Composites Science and Technology》1985,23(3):171-199
The large scale social changes which influence the development of new materials are reviewed and the new materials and processing methods being developed in response to these are described and contrasted with some recent advances in composite materials science.The particular technologies described are injection casting and superplastic forming, high temperature reinforcement by in situ composites and mechanical alloying. Aluminium lithium alloys are compared with carbon fibre reinforced plastics and with SiC reinforced aluminium. The reasons for the interest in new ceramic materials are reviewed and methods used to toughen ceramics are explained. Fibretoughening i is the most effective. Finally the properties of the newest composites containing carbon fibres in thermoplastic matrices are reviewed. 相似文献
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本文对陶瓷基复合材料的循环疲劳研究现状及发展趋势进行了最新述评。主要内容有:非相变增韧陶瓷、相变增韧陶瓷、晶须(或纤维)增强陶瓷基复合材料的循环疲劳行为和疲劳裂纹扩展机理。最后,还对进一步研究陶瓷基复合材料的循环疲劳特性提出了一些粗浅的看法。 相似文献
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P. Greil 《Advanced Engineering Materials》2000,2(6):339-348
Engineering ceramics in the system Si–O–C–N–B manufactured from preceramic silicon containing polymers gain in significance with increasing availability of advanced precursor materials such as poly(carbosilane), ‐(silazane), ‐(siloxane) or ‐(borosilazane). While high temperature resistant Si–C and Si–N ceramic fibers are already used to reinforce ceramic matrix composites (CMC) in air‐ and spacecraft structures, novel products such as coatings, tapes, foams, and complex shaped components for medium and low temperature applications in the fields of energy, environmental, transportation, and communication technologies become more important in the future. Preceramic polymers offer the possibility of using versatile plastic shaping technologies as well as advanced laminated object manufacturing techniques. Properties can be varied in a wide range by tailoring the molecular structure and composition of the precursor polymer and by loading the polymer with intert or reactive filler powders. Partial conversion of the organic polymer into organic/inorganic hybrid materials yields novel materials which exhibit properties between polymers and ceramics. 相似文献
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From micro to nano: properties and potential applications of micro- and nano-filled polymer ceramic composites in microsystem technology 总被引:1,自引:0,他引:1
Hanemann T Boehm J Henzi P Honnef K Litfin K Ritzhaupt-Kleissl E Hausselt J 《IEE proceedings. Nanobiotechnology》2004,151(4):167-172
In microsystem technology, four important material classes are established either for the generation or the replication of microstructured surfaces: silicon, polymers, metals and ceramics. Composite materials consisting of a polymer matrix and ceramic fillers show improved thermomechanical properties in comparison to polymers and can be introduced as a new additional material class. The substitution of micro-sized ceramic fillers by nano-sized ceramics in composites has a strong influence on the composite's physical properties: the reduction of ceramic particle size down to the nanometre scale results in an improved sinter activity owing to the large surface area. The fabrication of dense ceramics is simplified and can be used for a rapid prototyping of microstructured ceramic parts. The addition of nano-sized ceramics with particle sizes of <40 nm to polymers allows the manufacturing of transparent polymer based composites with modified refractive indices for use in polymer waveguides. The influence of the ceramic particle size, the ceramic content and different dispersion methods on the composite's physical properties are discussed. 相似文献
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Chongzhen Du Chuanzhen Huang Shijie Li Hanlian Liu 《Advanced Engineering Materials》2023,25(20):2300564
The design of the lamination structure based on bionic shell pearl layer is a successful method for toughening ceramics. Lamination with strong bonding interfaces is used to improve the mechanical property and low fracture toughness of ceramic cutting tools. Based on the idea of demand–design–preparation–analysis–failure, the development and research progress of laminated ceramic tools are reviewed herein. The research status of design, interlayer diffusion reaction, residual stress, toughening mechanism, and crack propagation path of the biomimetic laminated ceramic composite tool materials is mainly introduced. The major topics of current research include the creation of material systems, the evolution of microstructure, and the assessment of macroscopic mechanical properties. The entire mechanical properties of laminated ceramic tools are significantly influenced by the multicomposition design of the ceramic material system and the optimization design of structural parameters of layer number and layer thickness ratio. However, the research on the practical cutting application of laminated ceramic tools is limited. Cutting tool wear characteristics vary between laminated and homogeneous ceramic tools. The development of useful laminated ceramic cutting tools can greatly benefit from the study on failure mechanisms of laminated ceramic tools. 相似文献
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G. M. Gladysz M. Schmücker K. K. Chawla H. Schneider D. L. Joslin M. K. Ferber 《Materials Characterization》1998,40(4-5):209-214
The absence of a chemical reaction at an interface is conventionally thought to be an important criterion in producing a tough ceramic matrix composite (CMC). As a result of this criterion, interphases in CMCs were chosen on the basis of their chemical reactivity. A weak interface results in crack deflection, crack bridging, and, in fiber-reinforced ceramics, fiber pullout, resulting in an increased fracture toughness. In this paper, we present microstructural observations on alumina (Al2O3)–barium zirconate (BaZrO3) laminated composites wherein the reaction products that develop during processing resulted in sharp interfaces and appear to be weak enough to deflect cracks. These in situ reaction products in Al2O3–BaZrO3 laminated composites were characterized with the use of a scanning electron microscope, an electron microprobe, and a transmission electron microscope. The phases that develop, ZrO2, BaO·Al2O3, and BaO·6 Al2O3, produced sharp interfaces and are arranged in a sequence that could be predicted by using information from the phase diagram. 相似文献