Home About us Contact
|
Home About us Contact | ||
|
|
||
Alumina Matrix (alumina + matrix)
Selected AbstractsA Novel Processing Route to Develop a Dense Nanocrystalline Alumina Matrix (<100 nm) Nanocomposite MaterialJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2003Guo-Dong Zhan A dense 3-mol%-yttria-stabilized tetragonal zirconia polycrystalline (3Y-TZP) toughening alumina matrix nanocomposite with a nanocrystalline (<100 nm) matrix grain size has been successfully developed by a novel processing method. A combination of very rapid sintering at a heating rate of 500°C/min and at a sintering temperature as low as 1100°C for 3 min by the spark-plasma-sintering technique and mechanical milling of the starting ,-Al2O3 nanopowder via a high-energy ball-milling process can result in a fully dense nanocrystalline alumina matrix ceramic nanocomposite. The grain sizes for the matrix and the toughening phase were 96 and 265 nm, respectively. A great increase in toughness almost 3 times that for pure nanocrystalline alumina has been achieved in the dense nanocomposite. Ferroelastic domain switching without undergoing phase transformation in nanocrystalline t -ZrO2 is likely as a mechanism for enhanced toughness. [source] Platinum Nanoelectrodes Embedded in an Insulating Alumina Matrix: An Innovative Approach,CHEMICAL VAPOR DEPOSITION, Issue 4 2005A. Battiston A novel strategy, based on MOCVD, has been employed for preparation of ensembles of platinum nanoelectrodes. Pt/Al2O3 films with different Pt loading were deposited in just one step on glass capillaries. Nanocomposite films with varying Pt/Al atomic ratios were investigated by both cyclic voltammetry and TEM. Ensembles of nanoelectrodes with either overlap or no overlap of the diffusion layers of each nanoelectrode are obtained, depending on the Pt loading. From TEM measurements average Pt particle size of 3 , 7 nm was determined (Figure). [source] Percolative Mechanism of Aging in Zirconia-Containing Ceramics for Medical Applications,ADVANCED MATERIALS, Issue 6 2003C. Pecharromán For biomedical applications, zirconia-toughened alumina ceramics (see Figure) would be very appropriate materials, provided that the zirconia content is kept below the percolation threshold (upper limit of 16 vol.-% 3Y-TZP inside an alumina matrix). That the concept of a percolation threshold is relevant when talking about aging degradation, is demonstrated by comparing specular IR reflectance measurements with aging experiments. [source] Nanoporous oxides of refractory metals: fabrication and propertiesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008S. K. Lazarouk Abstract A new approach to fabrication of nanoporous oxides of refractory metals is presented. It is based on the magnetron co-sputtering of aluminum and refractory metal (titanium, niobium or tungsten) followed by porous electrochemical anodization of the composite film and selective etching of alumina. The nanoporous oxide films with a thickness up to 5 µm were fabricated and studied. The porosity of the oxide films characterized by the surface area of 230 , 460 m2/cm3 can betuned by the aluminum content in the as-deposited composite films. The pore diameters are found to be varied in nanometer and subnanometer ranges. The parameters of porous titania within porous alumina matrix for different titanium concentrations are presented. The fabricated porous composite oxide films are characterized by the refractive index in the range from 1.45 to 1.77. The dielectric permeability for these films is found to be varied from 6.7 to 24. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||