共沉淀法合成Bi掺杂钛酸钡基介电陶瓷的研究

采用化学共沉淀法合成了性能良好的Bi掺杂钛酸钡基介电陶瓷粉料，研究了合成工艺中的几个主要因素，研究了Bi掺杂量对材料性能的影响；利用SEM、XRD分析了材料微观结构，探讨了材料的介电性能与微观结构的关系。     

合成方法对高吸水性材料结构与性能的影响探讨

分别采用水溶液法和泡沫体系分散聚合法合成CMC—g—PAA高吸水性材料，对比了两种材料的结构及吸液性能。结果表明，泡沫体系分散聚合法合成的材料具有多孔结构，密度较小，吸液性能优于水溶液法合成的材料；泡沫体系分散聚合法合成的材料具有低温敏感性，两种方法合成的材料都具有良好的pH响应性。     

表面活性剂在磷酸锌低热固相合成中的应用

利用低热固相化学反应法开展磷酸锌结构材料合成研究，在不同表面活性剂存在下，以不同锌盐为原料，得到了微米级棒状结构、超细零维球状结构、纳米级空心球状结构及纳米级空心球棒状结构，并应用TEM和SEM等手段对产物结构、形貌和尺度的差异进行了表征。得出可以通过适当的实验设计，找到利用低热固相化学反应法合成磷酸锌特定结构材料的方法的结论。     

溶胶凝胶法制备LiFePO_4F及其电化学性能研究

采用溶胶-凝胶法制备了锂磷铝石型晶体LiFePO_4F。采用X射线衍射法(XRD)和扫描电镜法(SEM)表征了所合成材料的结构和形貌;采用恒流充放电法以及交流阻抗法表征了所合成材料的电化学性能。结构表征结果表明,所合成的LiFePO_4F材料具有P1空间对称群,与天然锂磷铝石(LiAlPO_4(OH,F))为同一种结构,颗粒大小为400~600 nm;电化学测试结果表明,所合成的材料具有148 mAh·g~(-1)的初始比容量,同时循环性能优良。文章通过交流阻抗技术估算了锂离子在该种材料中的扩散系数,结果表明,该材料的锂离子扩散系数比未改性的橄榄石型LiFePO_4大3个数量级。     

层状结构KMSS-1应用于吸附锌离子

采用水热法合成层状结构的KMSS-1材料。用SEM、傅里叶红外光谱仪XRD及对合成的KMSS-1材料的形貌、结构和纯度进行表征。研究了该材料对锌离子的吸附性能,考察了KMSS-1材料吸附锌的动力学及等温吸附模型。电镜表征结果表明,水热温度为200℃成功合成出的样品形貌成片状,有着很好的层状结构。吸附锌的研究结果表明,在200℃下水热法合成的层状结构KMSS-1材料表现出较高的吸附性能,该层状结构KMSS-1材料对锌的吸附动力学模型符合准二级动力学,吸附等温线符合Langmuir等温吸附模型。将层状结构KMSS-1材料用于净化废水中的锌,结果较好。     

空气气氛中合成LiNi0.7Co0.3O2及其AA电池电化学性能

采用共沉淀法合成LiNi0.7Co0.3O2正极材料,采用X射线(XRD)和扫描电镜(SEM)表征不同温度下合成的材料,并研究了材料的电化学性能。结果表明:750℃空气气氛下合成的材料的结构较规整和有序度更好,电化学性能最好。4.2V首次放电比容量达到143 mAh/g,100次循环后仍保持在125.4 mAh/g,循环性能优良。     

模板法制备多孔炭材料的研究进展

模板法为各种有机和无机纳米材料的可控和定向合成开辟了一条全新的技术途径，近年来已经成为材料制备研究领域引人注目的新方法。本文就迄今为止模板法在制备具有规则结构的多孔炭材料领域的研究动态进行综述，介绍了多孔炭材料的模板法制备、应用前景及其可能的形成机制。     

水热法制备二氧化钛晶须

采用水热合成法制备了金红石结构的ＴｉＯ２晶须，对晶须作了Ｘ射线衍射结构研究分析和扫描电镜形貌观察，并对其合成机理作了简要探讨。     

松香基季铵盐引导合成新型介孔材料的研究

选择松香基季铵盐为结构引导剂合成介孔材料,利用其特有的三环菲刚性骨架结构成功合成出4个系列多种结构的新型介孔材料.采用X射线衍射、N2吸附-脱附和透射电镜等技术手段考察了不同合成参数对材料结构的影响.本研究首次以大基团非长链表面活性剂引导合成介孔材料,丰富了介孔材料的种类,拓展了介孔材料的合成路线.     

C60化学修饰的高分子功能材料研究（上）

本研究选择“Ｃ６０的高分子化学修饰和功能材料化研究”为主题，采用金属有机化学反应技术，以碳负离子为重要的合成前体物质，在常温常压下较效地合成了可溶性Ｃ６０化学修饰的高分子衍生物，并应用多种现代物理测试技术系统地研究了材料的结构物理化学性质及其功能化行为。     

窑具材料显微结构与热震稳定性相关性研究

本文分析了影响窑具材料热震稳定性的重要参数,找出显微结构与这些因素的内在联系,表明通过调整显微结构可获得良好的材料性能。     

复相陶瓷材料的设计原则

根据陶瓷材料在使用上的性能要求，设计和确定材料的组成、显微结构和工艺，是陶瓷材料研究的进步。陶瓷材料向多相方向发展，为陶瓷材料的晚思考余地。本文阐述了复相陶瓷瓣设计原则，显微结构的设计，不同相之间的化学共存，不同相之间的物理匹配。     

Evolution of the Microstructure of Dynamically Loaded Materials

The paper deals with the evolution of the microstructure in materials after explosive loading by the method of a hollow thick-walled cylinder. The materials considered differ in the type of crystal lattice and initial state (grain size and initial defect density). The role of crystal structure in the formation of the microstructure of single crystals and coarse-grain copper specimens formed under explosive deformation is investigated. The microstructures formed are compared with the corresponding strains. It is shown that during high-rate deformation, fragmentation of the structural elements occurs at all scale levels. The fragmentation mechanism and the associated properties depend on the initial structure and state of the material. The special features of the microstructure evolution in materials revealed in this work are taken into account in producing new materials by dynamic and quasidynamic methods.     

Reactive Processing in Ceramic-Based Systems

Reactive hot pressing is discussed as a processing method to form ceramic-based materials. Fundamental aspects of thermodynamics such as favorable Gibbs'-free energy changes, phase equilibria, and adiabatic temperature are presented as criteria for determining whether the desired reactions can be used to form dense materials. Two case studies are presented as examples to describe control of microstructure and properties. The fabrication of Al₂O₃–Nb and ZrB₂ are discussed with respect to the three thermodynamic criteria as well as the microstructure and properties of the materials that are produced.     

Microstructure design and preparation of Al2O3/TiC/TiN micro-nano-composite ceramic tool materials based on properties prediction with finite element method

The objective of this paper was to improve the accuracy of semi-empirical method used to design ceramic cutting tool materials. The mechanical properties were predicted by employing finite element model of material microstructure, so as to design microstructure and prepare new ceramic materials. Based on the Voronoi and randomness method, the microstructure model representing the complexity and randomness of micro-nano-composite ceramic material microstructure was established. Combining the representative volume element (RVE) of ceramic material microstructure with mechanical tests, the simulations of mechanical tests were conducted to acquire the flexure strength, fracture toughness and hardness of materials. The microstructure models with various parameters were designed and the material properties were predicted to determine the optimal microstructure parameters. Then, The ceramic cutting tool materials possessing the optimal microstructure parameters were developed for machining ultra-high strength steels. The results showed that the mechanical properties of ceramic materials first improved and then declined as the nano-scale TiC volume fraction increased. To obtain the best comprehensive mechanical properties, the contents of micro-scale TiN, TiC and nano-scale TiC were set as 20%, 10% and 10%, respectively. The prepared ceramic materials possessed the flexure strength of 881.4 MPa, the fracture toughness of 7.8 MPa m^1/2, and the Vickers hardness of 20.8 GPa. This research is beneficial to the development of cutting tool design theory and the improvement of the tool life.     

Recent Advances in the Control and Characterization of the Porous Structure of Pillared Clay Catalysts

Several methods have been developed and applied in recent years in the characterization of the structure of microporous materials, in general, and of pillared clays, in particular. In the present article, the latest results obtained in the control of the microstructure developed in alumina-pillared clays and various approaches used to the evaluation of the porosity of these materials are reviewed. These include the control of the microstructure developed in pillared clays by adjusting the several parameters involved in the synthesis process, and the evaluation of the porosity of pillared clays. Emphasis is given to the methods to evaluate the pore size and pore size distribution (PSD) of these materials. Two separate sections are devoted to review mathematical modeling studies and ¹²⁹Xe NMR spectroscopy of physisorbed Xe to investigate the microporous structural properties of these materials.     

磁场作用下冷冻铸造法制备仿生材料研究进展

随着科技的迅速发展,对材料的性能提出了更高的要求,迫切需要开发新型轻质高性能结构材料,即低密度、高刚度、高强度和高韧性等特点集于一身。生物材料经过数亿年的进化,形成了与环境和功能需求相适应的精细复杂结构,如贝壳珍珠层的“砖-泥”结构和螃蟹角质层的螺旋结构,它们均表现出非凡的机械性能和独特的功能特性,这启发了人们对于高性能材料的设计和构筑。目前发展的冷冻铸造法(即冰模板法)是制备仿生材料的一种有效方法,通常在温度梯度作用下定向凝固水基陶瓷浆料,经冷冻干燥后可获得具有精细结构的多孔陶瓷材料,随后对该多孔陶瓷填充软相-树脂后可获得仿珍珠贝结构陶瓷-树脂复合材料。为了进一步控制材料微观结构,研究人员对冷冻铸造过程施加磁场作用,最终发现材料的结构和性能均发生了明显变化。本文介绍了冷冻铸造法在控制材料微观结构以及制备仿生材料方面取得的一些进展,综述了施加磁场作用对冷冻铸造的影响,总结了施加磁场辅助的冰模板材料微观结构和机械性能变化规律。     

Recent Advances in the Control and Characterization of the Porous Structure of Pillared Clay Catalysts

Several methods have been developed and applied in recent years in the characterization of the structure of microporous materials, in general, and of pillared clays, in particular. In the present article, the latest results obtained in the control of the microstructure developed in alumina‐pillared clays and various approaches used to the evaluation of the porosity of these materials are reviewed. These include the control of the microstructure developed in pillared clays by adjusting the several parameters involved in the synthesis process, and the evaluation of the porosity of pillared clays. Emphasis is given to the methods to evaluate the pore size and pore size distribution (PSD) of these materials. Two separate sections are devoted to review mathematical modeling studies and ¹²⁹Xe NMR spectroscopy of physisorbed Xe to investigate the microporous structural properties of these materials.     

不同的烧失物对微孔莫来石性能的影响

莫来石的导热系数低、高温下体积稳定性好,适合用来制备轻质耐火材料。以硅石粉和工业氧化铝为起始物料,加入一定量的烧失物,通过在1350℃下煅烧6h制得了微孔莫来石轻质骨料。研究了碳黑、焦炭和无烟煤这三种烧失物对合成的莫来石骨料体积密度、气孔孔径分布、莫来石生成量及组织结构的影响。认为,不同的烧失物对微孔莫来石的体积密度、...     

Characterization of the Mechanical Behavior of Magnesia Spinel Refractories Using Image Correlation

The improvement in thermal shock resistance of refractory materials is among the crucial properties that interest researchers and industrials. The “flexibility” in terms of large strain‐to‐rupture is, up to now, an important parameter to develop such characteristic. This can be obtained by generating a network of microcracks within the microstructure of the material under mechanical solicitations. As an outcome, the mechanical behavior can vary from fragile to a large nonlinear one depending on the degree of microcracking present inside the material. In fact, this nonlinear behavior of ceramics related to their microstructure is behind the possibility to enhance the level of strain‐to‐rupture for a better accommodation to the high level of strain induced by thermal shock solicitations. This study is devoted to apply digital imaging correlation method to support mechanical behavior analysis for the evaluation of the thermal shock ability of refractory materials. In this paper, mechanical characterization of magnesia spinel materials has been carried out using different experimental tests. These nonlinear materials are characterized by a mechanical behavior strongly dependent on their microstructure.