Copper based hydrophobic ceramic nanocoating

A mechanism for the development of nanocoatings for the tiles industry by using copper nanoparticles has been proposed. A standard processing procedure in which ceramics were fast-firing at 1200 °C in air atmosphere simulating an industrial process was followed. The ceramic nanocoating was multifunctional having shine metallic aspect and hydrophobic characteristics. The surface crystallizations were studied by X-ray diffraction and corresponded to copper oxide nanocrystals. The hydrophobic response was based in the nanoroughness of the surface and correlated with the Cu⁺/Cu²⁺ ratio as determined by XANES. The cellular nano microstructure look biomimetic with the one of hydrophobic leafs. The development of the cellular nano microstructure was based on the Rayleigh-Bernard cells of a saturated glass during cooling in which thermal convection currents allow the crystallization of nanoparticles at the surface of the glass.     

Porous ceramic monoliths based on diatomite

Porous silica ceramics were obtained at low forming pressure and low sintering temperature by using diatomaceous earth as a silica source and boric acid as an inexpensive additive. The starting raw material, diatomite from surface coal mine Kolubara, Serbia, was purified from organic and inorganic impurities by using heat and chemical treatment. Boric acid was used as binding and sintering aid up to 2 wt%. Powder was compacted by using different pressures of 40, 60 and 80 MPa. The pressed samples were sintered at 850, 1000, 1150, and 1300 °C for 4 h in air. A relatively high porosity in the range of 60–70% is obtained for the samples pressed at 40, 60 and 80 MPa and sintered at 1000 °C. Median pore size diameters are in the range of macroporous up to 2 μm in the samples sintered at 1150 and 1300 °C. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scaning electron microscopy (SEM) and mercury porosimetry measurements were employed to characterize the phases, functional groups, microstructure and pore size distribution of the obtained samples. In addition, measurements of densities and open porosities by immersion technique, according to Archimedes principle, were used. The relations between mechanical properties (Young modulus, Poisson ratio, and compressive strength) versus content of boric acid in the investigated samples were studied and disscussed.     

Catalytic reactors based on porous ceramic membranes

This overview discusses some of the developments and outstanding opportunities in the field of catalytic reactors based on porous ceramic membranes, both inert and catalytic. This is an emerging area, where inputs from heterogeneous catalysis, material science and reactor engineering are playing the key roles. Rather than attempting a thorough review of the relevant literature, this work deals with some general concepts and then concentrates on a few selected examples that illustrate the application of membrane reactors.     

氧化铝基连续陶瓷纤维的发展现状

介绍了国内外氧化铝基连续陶瓷纤维的研究现状,并阐述了它在航天领域、机械制造领域和过滤材料方面的应用现状和发展前景。     

A thermostable composite ceramic based on cordierite

Aporous, thermostable composite material was developed from natural powders that form a cordierite matrix on sintering and a filler — fibrous nanostructure aluminum oxide powder with high porosity and reactivity. It was found that incorporation of the nanocrystalline aluminum oxide filler in the composite with the cordierite matrix causes the formation of a polyporous structure that increases the porosity and thermal stability and improves the heat-insulating properties of the material.     

Strengthened porous ceramic based on mullite and corundum

Data are provided for manufacturing technology and ceramic properties of porous ceramics of mullite-corundum composition. The ultimate strength in compression of this ceramic is several times higher than commercial porous aluminosilicate ceramics. Translated from Novye Ogneupory, No. 7, pp. 38–39, July 2008.     

SiC陶瓷基体及抗氧化涂层

介绍了5种主要SiC基体的成型方法,分别是化学气相渗透(CVI)、聚合物先驱体浸渍-裂解法(PIP)、液相硅渗透法(LSI)、反应烧结法、化学气相反应法(CVR)。阐述了各种基体的组织结构、致密效率及陶瓷基复合材料的性能,其中CVI+PIP/LSI的复合成型技术可达到优化的制备过程,提高基体的组织结构和致密化效率;C/C及C/SiC复合材料表面化学气相转换法SiC涂层及多层涂层技术是提高CMC抗氧化性能的有效途径,并已得到工程实际验证。     

Synthesis of a foam ceramic based on ceramic tile polishing waste using SiC as foaming agent

Due to the large amount of ceramic tile polishing waste generated in China, the recycling of this waste residue becomes important. Herein a foam ceramic was successfully produced by using ceramic tile polishing waste as main raw material. In this research, SiC was added as the foam agent, and the foaming mechanism was also investigated. The results showed that the best dosage of SiC was 1%. Furthermore, in order to obtain a foam ceramic with better structure, the sodium phosphate was added in raw materials as foam stabilizer. The influence of this addition on the microstructure and properties of foam ceramic was investigated. It was found that the optimum additive amount of sodium phosphate is 2–3%.