国内陶瓷论文文摘

这种纳米复相陶瓷材料的强度、韧性以及降低电阻率等方面的性能均达到国际水平。由于这种陶瓷是用几种陶瓷复合而成，并添加了具有磁性、电性、光性能的其它材料，因而它既拥有结构陶瓷的力学性能，又具备功能陶瓷的特殊功能。如由于磁性材料的添加，其电阻率大大降低，使其从高绝缘体变成可导电的材料，扩大了应用面，从而也使原来不可切割的陶瓷，如今可用电火花进行切割，大大降低了陶瓷材料的加工成本。     

多孔陶瓷的研究现状与应用

多孔陶瓷，又被称为微孔陶瓷、泡沫陶瓷等。它是具有均匀分布的微孔(气孔率可高达50％-90％)，体积密度小。有着三维立体网络骨架结构，且相互贯通的陶瓷制品。它具有发达的比表面积及独特的物理表面特性，对液体和气体介质有选择的透过性、能量吸收或阻压特性。加上陶瓷材料本身独有的耐高温、耐腐蚀等优异特性，使多孔陶瓷在气体液体过滤、净化分离、化工催化载体、高级保温材料、生物植入材料、吸声减震和传感器材料等许多方面得到广泛应用。     

纳米陶瓷材料及其制备与应用

由于硬度高、耐高温、耐磨损、质量轻和导热性好，陶瓷材料是现代工业三大基本材料之一，但其脆性大、韧性小而限制了在一些特殊领域的应用。纳米材料及技术运用到陶瓷材料中极大地改善了它的应用性能。本文比较了传统陶瓷与纳米陶瓷的优缺点，介绍了纳米陶瓷材料材料的特性和种类，以及制备方法、应用和国内研究现状。     

泡沫陶瓷材料的制备及多功能性

泡沫陶瓷是一种重要的多孔材料,由众多的气孔在空间通过各种方式排列而成,因其特殊的结构具有多功能性。根据国内外最新文献,本文综述了泡沫陶瓷材料的制备方法,介绍了泡沫陶瓷优异的过滤与分离性、吸声性、隔热性等多种功能性。     

碳化硅多孔陶瓷制备与应用

主要以SiC多孔陶瓷材料为例，综述了多孔陶瓷的4种常用制备方法，即添加造孔剂法，发泡法，有机泡沫浸渍法和溶胶-凝胶法的工艺特点和制品特性，并且列举了制备SiC多孔陶瓷材料的6种特殊方法，包括含硅树脂热解法、固相反应烧结法、气相反应渗入法、流延成型法、固态烧结法和浸渍热解法。文中还给出了多孔陶瓷的性能与表征，介绍了SiC多孔陶瓷材料在过滤材料、催化剂载体、热工材料、吸声材料和复合材料骨架材料方面应用情况，为SiC多孔陶瓷材料的研究和应用开发提供指导意义。     

谈工程陶瓷材料的结构功能及其运用

陶瓷材料作为材料业的三大支柱之一,在日常生活及工业生产中起着举足轻重的作用。陶瓷材料是人类应用最早的材料之一。它是一种天然或人工合成的粉状化合物,经过成型或高温烧结,由金属元素和非金属的无机化合物构成的多相固体材料。陶瓷材料具有耐高温、耐腐蚀、耐磨损、原料丰富、成本低廉等诸多优点而被人一直关注。1工程陶瓷材料的组成结构与功能特点陶瓷是古老而又新型的材料,它是用天然或     

利用菌类物质获得微孔级的纳米材料

由于多孔材料已经在过滤、通风、材料装卸、吸附剂、结构材料以及传感器等众多领域中显示出了强大的功能，其制备方法已经成为多孔材料研究的热点课题。弗吉尼亚理工大学材料科学与工程学院的研究人员Manjooran等人在其发表在《陶瓷学报》上的研究性文章中称，利用单细胞真菌在陶瓷中制成了微米级范围的孔径，并对这种纳米结构的多孔陶瓷材料进行了性能研究与测试。     

多孔网状Si3N4陶瓷增强体的制备

选用具有连通气孔的网状聚氨酯海绵作为骨架,利用有机泡沫浸渍的Si3N4浆料工艺,以Al粉、Al2O3和ZrO2作为Si3N4陶瓷材料的烧结助剂,采用2次挂料及2步烧结工艺制备了性能良好的多孔陶瓷骨架。在相同烧结工艺条件下,多孔陶瓷的抗压强度随着孔隙率的下降逐渐增加。当烧结温度为1400℃时,多孔陶瓷具有最佳的烧结效果,既能保持很高的通孔率,又保证了材料具有较高的抗压强度。     

泡沫陶瓷材料的研究进展

介绍了泡沫陶瓷的特性、制造工艺，并列举了泡沫陶瓷在几个方面的主要应用。指出了当前陶瓷材料的研究热点和今后发展需要解决的问题。     

行业动态

超硬耐腐陶瓷研制成功日前,国外研制成功一种超硬耐腐陶瓷。这种陶瓷是由酸性火山灰、氧化铝粉和碳粉配料成形,在氮气中于1300~1400℃加热氮化,再升温至1500~1700℃烧结而成。这种陶瓷自身还可用作研磨材料,与其它陶瓷粉末复合,能获得具有耐磨、耐腐蚀的耐火材料。它适宜生产机械部件、保护管、坩埚等高硬度、高耐腐蚀、高强度的致密陶瓷制品。燃烧器喷嘴用陶瓷材料由美国开发研制成功位于美国纽约州的aremcd公司成功开发出一种低成本、可加工的新型铝硅酸盐陶瓷材料,十分适合于制作燃烧器的喷嘴,并可用于制作多种工业零部件如电绝缘子、热绝缘子、铜焊件、焊接防护板等等。这种材料可在氧化、还原、真空等各种环境     

Some technological laws and properties for highly porous ceramic concretes

Conclusions Using ceramic concrete made from zirconia as an example we formulated conditions and established the main technological laws for obtaining highly porous ceramic concretes.We analyzed the composition and microstructure of the ceramic concrete from the point of view of the existence in the system of noncompensated shrinkage. It is shown that for ceramic concrete with a high bond shrinkage during drying and heat treatment, with the purpose of reducing the shrinkage stresses in the system, it is necessary to use multifraction (coarse, medium, and fine) fillers.We show the effectiveness of using, as one of the filler components, removable poreforming additive, based on foamed polystyrol.The optimum region of the grain-size distribution of the components was established; this comes within the true specific volumes in the structure of the shaped ceramic concrete and amounts to 20–30% bond, 20–25% fine (0.1–0.4 mm) and 25–40% coarse (5–10 mm) filler made from waste zirconia foamed ceramics, and 20–25% foamed polystrol (0.63–1.6 mm).We studied certain properties of the resulting materials with a porosity of 60–75% and a compressive strength of 5–20 MPa.Compared with other highly porous materials, for example, foamed ceramics, the highly porous ceramic concretes have technological advantages (much lower water capacity of the shaping system, reduced shrinkage in drying and firing) and also improved operating characteristics, for instance, thermal conductivity, thermal-shock resistance and volume constancy.Translated from Ogneupory, No. 2, pp. 20–25, February, 1984.     

Preparation and performance of lightweight porous ceramics using metallurgical steel slag

In this paper, porous ceramics with high porosity and low bulk density were prepared by using steel slag and kaolin as main raw materials and polyurethane sponge as template. The effects of steel slag particle size, zirconia addition, the solid content of the slurry, and the addition of polycarboxylic acid water-reducing agent on the properties of ceramics were studied. In addition, by adding a surfactant (Sodium dodecyl sulfate) to form fine pores on the original framework of the three-dimensional network porous ceramic, the shortcomings of the single as well as the uncontrollable density and porosity of the porous ceramic, which are produced by the template method, are improved. When the grinding time of steel slag is 90 min, the content of zirconia is 3% wt, the solid content of ceramic slurry is 64% wt, and 0.6% wt polycarboxylic acid water-reducing agent and 0.4% of surfactant are added, the prepared porous ceramic skeleton is clear and good. The porous ceramic has a low bulk density (as low as 157.869 kg/m³), high porosity (about 94.05%) and high compressive strength (0.2 MPa). The crystalline phase of it is mainly composed of anorthite, gehlenite, forsterite and quartz. The addition of zirconia, water-reducing agent and surfactant only changes the macrostructure of porous ceramics, and does not change its crystal phase composition. The preparation of porous ceramics from steel slag not only solves the recycling problem of steel slag, but also provides a good substitute for main raw materials of porous ceramics.     

Microstructure of ceramic foams

This paper describes the preparation of ceramic foams by expansion of a ceramic suspension based on a polyurethane system. The microstructure and degree of reticulation of the foamed ceramic were examined and analysed with the help of a simple geometrical model. Like the porous ceramics prepared by the replica processing method, these foamed ceramics possess open cells in a nearly equiaxed shape but the cell size is much finer. The ratio of the window size to the cell size is a useful parameter for characterising the geometry of the foam and is related to the qualitative concept of degree of reticulation. For a face centred cubic array of cells it is related geometrically to the volume fraction of porosity and this relationship is tested using microstructural measurements for a range of ceramic foams.     

Opportunities of porous ceramics fabricated by gelcasting in mitigating environmental issues

Porous ceramics fabricated by gelcasting bring many unique capabilities in mitigating environmental issues, particularly waste recycling and neutralization of hazardous emissions. Potential opportunities for using gelcasting technique in setting mechanically foamed slurry can be described by adaptable designing and modification of the foamed slurry characteristics with a goal of preserving the environment. In this paper, we describe three directions of porous shaping routes through gelcasting in an attempt to mitigate environmental issues. Firstly, the fabrication of porous ceramics with inclusion of non-through holes and double-layered porous structure was described as an effective means of reducing pressure drop during filtration. Secondly, the non-toxic gel-former has been successfully applied to the gelling of waste loaded foamed slurry under ambient condition. The process has great benefit not only for the fabrication of lightweight ceramics with multifunction purposes, but also for the development of endless recycling system. Lastly, the pyrolysis of gelcast dried porous ceramics under oxygen-free atmosphere has provided a promising material as a filter having a heating function for oxidation of hazardous emissions.     

Mechanical and electrical properties of superplastically foamed titania-based ceramics

Ceramic monofoams based on titania were fabricated using superplastic deformation driven by the evolution of gas from a foam agent. Titania-based polyfoam with porosities of up to 25% can be fabricated by dispersing only 1 mol% of foam agent (silicon carbide). When the mechanical strength of superplastically foamed titania was compared with that of fully densified titania and conventionally fabricated porous titania, the superplastically foamed ceramics retained 70% of the mechanical strength of the dense ceramics, while that of the conventional porous ceramic decreased to 40%. Niobium-doped semiconducting titania polyfoam was also fabricated. The electrical resistivity and affect of ambient humidity were similar to those of the dense ceramics.     

高孔隙多孔陶瓷材料的制备工艺

从分析网状结构多孔陶瓷材料的孔隙形成机理着手，描述了高孔隙网状结构陶瓷材料的制备工艺。其中主要包括高孔隙纤维网状结构陶瓷材料的制备工艺及高孔隙泡沫陶瓷材料的制备工艺。     

粉煤灰发泡陶瓷的制备及性能研究

面对日益匮乏的陶瓷原料,利用固体废弃物来制备发泡陶瓷已是当今趋势。以粉煤灰为主要原料,研究铬渣掺量、碎玻璃掺量和粉磨工艺对粉煤灰发泡陶瓷的影响。结果表明,掺入适量的铬渣可改善粉煤灰发泡陶瓷的性能,小掺量的碎玻璃对粉煤灰发泡陶瓷的性能影响较小。当原料配比为m(粉煤灰)∶m(铬渣)∶m(长石)∶m(碎玻璃)=60∶10∶20∶10时,采用湿法粉磨3 h,可以制得平均孔径为0.64 mm,体积密度为368.54 kg/m³,抗压强度为8.11 MPa的发泡陶瓷。     

Fabrication of Ceramics with Complex Porous Structures by the Impregnate–Freeze-Casting Process

The ceramics with complex porous structures were fabricated by a combination of impregnating and freeze-casting process. The polyurethane sponge was impregnated in the mold with 20 vol% of aqueous alumina slurry, and then the bottom of the cast body was kept at a constant cooling rate of 6°C/min to induce unidirectional solidification. After drying and sintering of the green part, porous ceramic with obvious lamellar architectures was prepared. The lamellae thickness and interlayer distance were as large as ∼9 and ∼15 μm, respectively. The large pores, which resulted from the burn-up of sponge struts were homogeneously distributed in the sample. The use of the porous template introduced some local interruption of the lamellar structures. However, high compression strength for the porous ceramic can still be obtained.     

Production and properties of highly porous zircon materials

Conclusions We proposed, using zircon as an example, the principle of forming pores of two types — cellular and capillary — for obtaining highly porous (up to 90%) ceramics. It consists of a combination of the foam method and the introduction of removeable foamed polystyrene. At the stage of forming and drying the system is distinguished by a high volume constancy, uniformity of properties, and the possibility of carrying out rapid drying.On the basis of a zircon suspension as the bond and crushed zircon foamed ceramics as the filler we obtained a highly porous ceramic concrete with a porosity of 50–70% and a compressive strength of 12–24 MPa.A marked influence on the properties of the resulting materials is exerted by the microcracks formed as a result of the removal of the expanded polystyrene (PPS) in the foamed ceramic, and the presence of uncompensated shrinkage in the ceramic concrete. With an increase in the value of the uncompensated shrinkage from 0 to 7%, the thermal-shock resistance of the ceramic concretes is increased 1.3 times and the thermal conductivity is reduced by a factor of 1.25.Translated from Ogneupory, No. 7, pp. 20–25, July, 1984.     

Preparation of a reticulated ceramic using vegetal sponge as templating

This paper describes the preparation of a reticulated ceramic that combines the morphology of vegetal sponge with ceramic properties, such as thermal stability, resistance to chemical attack, elevated porous degree and reticulation. In this method sponge samples are dipped into a colloidal suspension of 50% clay, 35% feldspar and 15% sand (w/w), followed by drying and heat treatment at 1175 °C for 120 min. Thermogravimetric analysis (TGA) of the vegetal sponge showed that the organic material is completely eliminated at temperatures around 515 °C. X-ray diffraction (XRD) analysis of the reticulated ceramic indicated the presence of mullite and cordierite. Scanning electron microscopy (SEM) of the reticulated ceramic showed the presence of two groups of porous ceramics, one in the range of 5–10 μm which was formed along the wall of the filaments, and another formed as a negative structure of the sponge filaments, measuring approximately 300 μm of diameter.