Sialon陶瓷的研究进展

简要论述了Ｓｉａｌｏｎ陶瓷的结构和性质,介绍了目前国内外Ｓｉａｌｏｎ陶瓷的研究概况,系统阐述α’－Ｓｉａｌｏｎ陶次必Ｓｉａｌｏｎ复相陶瓷的研究进展。     

氮化物结合耐火材料与氧化物耐火材料的抗侵蚀性能研究

比较了Ｓｉ３Ｎ４结合ＳｉＣ，Ｓｉａｌｏｎ结合刚玉，ＡｌＮ结合刚玉，ＡｌＯＮ结合刚玉材料与刚玉砖和粘土砖的抗高炉渣侵蚀及抗钢水侵蚀性。结果表明：与刚玉质，粘土质耐火材料相比，氧化物／非氧化物复相材料显示优良的抗渣透性和抗渣浸浸蚀性。     

纳米陶瓷球作为催化剂载体

能用于高温(如发动机组件)和用作耐腐蚀和耐磨损工具的一种陶瓷,命名为“Ｓｉａｌｏｎ”已由日本Ｙｏｋｏｈａｍａ国家大学的材料工程教授ＫａｔｓｕｔｏｓｈｉＫｏｍｅｙａ成功合成出直径为200～500ｎｍ的空心球。Ｋｏｍｅｙａ说,这是首次合成的α型而不是β型的Ｓｉａｌｏｎ。此多孔α型材料的潜在应用包含催化剂载体和微型过滤器。包含通常的Ｓｉａｌｏｎ成分(氮化硅和氧化铝)和钙的新材料,其合成方法是将含有5%～6%碳酸钙和约20%碳粉的二氧化硅和氧化铝混合物经还原而获得,还原过程在1450℃和105Ｐａ压力下,并于氮气保护下进行2ｈ完成。…     

Y_2O_3-SiO_2 添加剂对 AlN/SiC_W 复合材料性能的影响

利用ＸＲＤ、ＳＥＭ、ＥＰＭＡ和ＨＲＥＭ等测试技术系统地研究了Ｙ２Ｏ３－ＳｉＯ２添加剂对ＡｌＮ／ＳｉＣＷ复合材料力学性能及高温抗氧化性能的影响。结果表明：Ｙ２Ｏ３－ＳｉＯ２添加剂可有效地改善材料的力学性能,材料的氧化过程也是其热处理增强过程。添加剂组成接近其低共熔点时,材料随氧化时间的延长而得到增强增韧,且增幅最大,其最佳掺量为１０ｗｔ％。氧化处理改变了粒界玻璃相的相组成,玻璃相与ＡｌＮ颗粒发生作用,生成ＡｌＮ多形体２ＨδＳｉａｌｏｎ相,形成对材料有益的空间交错的结构。     

纳米级SnO2气敏材料制备及结构分析

制备敏感元件的原材料粉粒越细越好．介绍了以明胶作分散介质用溶胶－明胶法制备纳米级ＳｎＯ２敏感材料的工艺方法．制备的ＳｎＯ２材料粒径小于１０ｎｍ．实验研究了热处理的温度和时间对ＳｎＯ２材料粒径的影响,并进行了理论上的解释．对制备的ＳｎＯ２材料进行了透射电子显微镜、比表面积测试和Ｘ射线衍射等方法的测试分析,给出了测试分析结果．     

一种陶瓷复合材料基体—BAS玻璃陶瓷

纤维增强的ＢＡＳ玻璃陶瓷被美国的ＮＡＳＡ（国家宇航局）Ｌｅｗｉｓ研究中心认为是２１世纪先进高温发动机结构材料的候选材料，是目前发达国家正在致力研究的陶瓷复合材料基体材料之一．结合笔者所作的探索性研究工作，本文简要介绍ＢＡＳ玻璃陶瓷的晶体结构、性能、制备方法和研究现状．阐述高温溶化法制备ＢＡＳ玻璃的缺点及低温合成法（溶胶－凝胶法）制各ＢＡＳ玻璃的优点和可行性．提出在开展ＢＡＳ玻璃陶瓷研究方面，我国和先进国家差距并不大，有可能进入世界先进行列．     

被动式太阳房相变材料的实验研究

论述相变材料是被动式太阳房理想的贮热材料，其溶点宜选择为１２℃。通过实验，初步探明Ｎａ２ＳＯ４·１０Ｈ２Ｏ（芒硝）中加入适量的ＮＨ４Ｃｌ、ＮａＣｌ等物质可以达到要求。本文还介绍了不用冷冻设备制取Ｎａ２ＳＯ４·１０Ｈ２Ｏ的方法     

基于MS—windows的图形用户界面开发系统GUIDS

介绍了一种通用性较强的ＧＵＩＤＳ，ＧＵＩＤＳ是基于ＭＳ－ｗｉｎｄｗｓ的图形用户界面开发系统，阐述了ＧＵＩＤＳ的设计思想与实现方法，了系统找基本功能和特点。     

活性钎料钎接Si3N4陶瓷的机理研究

通过钎料中常用活性材料与被钎陶瓷Ｓｉ３Ｎ４之间的物理现象和化学反应，讨论了活性材料所起的作用，即通过活性金属与Ｓｉ３Ｎ４陶瓷的化学反应形成反应过渡层而结合，同时活性材料改善了钎料在Ｓｉ３Ｎ４陶瓷表面的漫流性能。但因为反应产物与Ｓｉ３Ｎ４陶瓷热物理性能相差较大，故活性材料的加入量应限制在一定范围以内。用Ａｇ－Ｃｕ－Ｔｉ钎料钎接Ｓｉ３Ｎ４／钢时，在Ｓｉ３Ｎ４／钎料过渡区生成了富ＴｉＮ层和富Ｔｉ３Ｓｉ５     

金刚石工具头超声波旋转加工的实验研究

研究了金刚石工具头超声波旋转加工方法的可行性及加工参数与材料去除率的关系。在研究超声加工、超声旋转加工和金刚石工具的基础上，借助ＳＥＭ分析其典型塑性材料和脆性材料的加工形貌，初步讨论了该方法去除材料的机理。     

Bi2Sr2Co2Oy热电材料的制备

为了研究Bi2Sr2Co2Oy热电陶瓷的不同制备方法,实验采用固相反应法和溶胶-凝胶法制备Bi2Sr2Co2Oy陶瓷．用XRD,SEM等表征技术研究了样品的物相及显微组织形貌．结果表明：样品为单相,组织均匀,为层片状结构,且具有明显的c轴择优取向．     

不同锆锡比对PLZST铁电陶瓷相变行为的影响

对不同锆锡比的Pb_(0.97)La_(0.02)(Zr_(0.12+x)Sn_(0.7-x)Ti_(0.18))O_3铁电陶瓷的铁电和相变行为进行了系统的研究,阐明了组成和温度对PLZST铁电陶瓷的相变效应的影响规律.研究结果表明:PLZST铁电陶瓷均呈现典型的铁电体电滞回线.随着温度的升高,PLZST12/70/18,PLZST52/30/18,PLZST62/20/18发生铁电-顺电相变,PLZST22/60/18,PLZST32/50/18,PLZST42/40/18为铁电-反铁电-顺电相变.     

Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电弛豫特征

采用固相反应法制备了Ba1-xBix(Ti0.9Zr0.1)O3(x=0.01,0.02,0.03,0.04)陶瓷,X射线衍射分析表明所有样品均是四方晶体结构,3%mol的Bi3+能够完全溶入钙钛矿晶格中.不同频率下Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电温谱显示所有样品均表现出弥散相变的特征,在x≥0....     

Ba_（1-x）Bi_x（Ti_（0.9）Zr_（0.1））O_3陶瓷的介电弛豫特征

采用固相反应法制备了Ba1-xBix（Ti0.9Zr0.1）O3（x=0.01,0.02,0.03,0.04）陶瓷,X射线衍射分析表明所有样品均是四方晶体结构,3%mol的Bi3＋能够完全溶入钙钛矿晶格中。不同频率下Ba1-xBix（Ti0.9Zr0.1）O3陶瓷的介电温谱显示所有样品均表现出弥散相变的特征,在x≥0.02的三组样品又表现出弛豫铁电体的特征。通过纳米极性微区和畴壁探讨了弛豫现象产生的机理。     

Preparation and piezoelectric properties of CuO-added (Ag<Subscript>0.75</Subscript>Li<Subscript>0.1</Subscript>Na<Subscript>0.1</Subscript>K<Subscript>0.05</Subscript>)NbO<Subscript>3</Subscript> lead-free ceramics

CuO-doped (Ag_0.75Li_0.1Na_0.1K_0.05)NbO₃ (ALNKN-xCuO, x = 0–2mol%) lead-free piezoelectric ceramics were prepared by the solid-state reaction method in air atmosphere. The effects of CuO addition on the phase structure, microstructure, and piezoelectric properties of the ceramics were investigated. The experimental results show that the ALNKN ceramics without doping CuO possess rhombohedral phase along with K2Nb6O16-type phase and metallic silver phase. For all of the CuO-doped ALNKN ceramics, a pure perovskite structure with the orthorhombic phase was obtained by enclosing the samples in a corundum tube. A homogeneous microstructure with the grain size of about 1 μm was formed for the ceramics with 0.5mol% CuO. The grain size increases with increasing amount of CuO. The temperature dependence of dielectric properties indicates that the ferroelectric phase of the ALNKN-xCuO ceramics becomes less stable with the addition of CuO. The ceramics with x = 1mol% exhibit relatively good electrical properties along with a high Curie temperature. These results will provide a helpful guidance to preparing other AN-based ceramics by solid-state reaction method in air atmosphere.     

Dielectric Properties of Unfilled Tetragonal Tungsten Bronze Ba_4PrFe_(0.5)Nb_(9.5)O_(30) Ceramics

In order to found new dielectrics ceramics in tungsten bronze structure, unfilled tungsten bronze(TB) ceramics with nominal formula Ba_4PrFe_(0.5)Nb_(9.5)O_(30) were prepared by the solid state reaction method. The microstructure and dielectric properties were studied using powder X-ray diffraction, field emission scanning electron microscope, and variable temperature dielectric test system. The results show that the ceramics have a single phase and belong to the space group of P4bm with the cell of a = b = 12.4839(3) ?, c = 3.9409(5) ?, V = 614.192(2) ?3. The frequency dependent dielectrics properties show that the ceramics have a Debye-like relaxation at room temperature, while the temperature dependent dielectrics properties indicate that the ceramics are a relaxor and the relaxation is due to the nanopolars and oxygen vacancies. The ceramics have a potential application in electronic ceramics as temperature-stable multilayer ceramic capacitors.     

铁微量掺杂对二钛酸钡陶瓷介电性能的影响

采用常规固相反应法,以碳酸钡、二氧化钛和三氧化二铁为原料,制备微量铁掺杂的二钛酸钡陶瓷,研究了铁掺杂含量对二钛酸钡陶瓷的相纯度、相对密度和介电性能的影响.采用X射线粉末衍射仪检测二钛酸钡陶瓷的相成分,利用精密阻抗分析仪测量其介电性能.结果表明,微量铁元素进入了二钛酸钡晶格,能够获得单相二钛酸钡陶瓷的最大铁掺杂量在0.5%～1%之间.随着铁含量的增加,铁电相变居里温度快速减小,从未掺杂时的415 ℃降至铁含量为0.02%时的376 ℃和铁含量为0.5%时的324 ℃.同时介电常数逐渐减小,介电峰不断发生宽化,但并没有导致弛豫性铁电体的出现.微量铁元素的掺杂在实验测量误差范围内对陶瓷的密度影响不大.     

Degration of Partially Stabilized Zirconia Ceramics under an Applied Stress

Partially stabilized zirconia ceramics were sintered using fine powder of ZrO2-3mol % Y2O3 prepared by the chemical co-precipitation method. The tetragonal-to-monoclinic phase transformation in ZrO2 ceramics during the aging in boding water and the effect of an applied stress of 100MPa were mainly investigated.The degradation of ZrO2 ceramics is considered to be caused by the reaction between Y2 O3 and H2O, which leads to a decreasing in the stability of tetragonal phase of ZrO2. It is found that the tensile stress improves the driving force of the phase transformation and acoelerates the degradation while the compressive stress has no obvious effect on the deeradation.     

铌掺杂Bi3.15Nd0.85Ti3O12陶瓷材料铁电性能

采用高温固相法制备了铌掺杂Bi3.15Nd0.85Ti3O12铁电材料.利用X射线衍射仪、拉曼光谱仪分析样品物相结构,阻抗分析仪和铁电性能测量仪测试电性能.发现制备的陶瓷材料均为单一的层状钙钛矿结构,反映TiO6八面体内部振动情况的850cm-1处拉曼峰随着Nb掺杂量的增加明显上移,表明:TiO6参与取代过程,Ti4+被具有较小离子半径的Nb5+取代.Nb的引入使样品的介电损耗明显降低,居里温度呈下降趋势.随着Nb掺杂量的增加,材料的剩余极化强度先增大后减小,当x=0.03时2Pr达到极大值19.3μC/cm2,矫顽场为57.5 kV/cm.     

层状钴酸锶铋热电陶瓷制备的研究

实验采用熔融法和普通固相烧结法制备镧掺杂钴酸锶铋陶瓷．利用TG—DSC,XRD和SEM等测试方法对陶瓷样品热分解过程、物相和形貌进行表征．实验结果表明：熔融法能够更好的制备出致密度高、晶粒发育完整、片层结构明显、晶粒具有一定取向的陶瓷样品．制备工艺对样品的显微结构和热电性能有重要影响．