Modern high-density oxide ceramics with a controlled microstructure. Part VI. Fabrication of light-transmitting oxide ceramic materials

1997 ◽  
Vol 38 (7-8) ◽  
pp. 253-259 ◽  
Author(s):  
E. S. Lukin
2009 ◽  
Vol 3 (1-2) ◽  
pp. 13-17 ◽  
Author(s):  
Karel Maca

The author's experience concerning the influence of the choice of different pressureless heating schedules on the final microstructure of oxide ceramic materials is summarized in the paper. Alumina, ceria, strontium titanate, as well as tetragonal (3 mol% Y2O3) and cubic (8 mol% Y2O3) zirconia were cold isostatically pressed or injection molded and pressureless sintered with different heating schedules - namely with Constant-Rate of Heating with different dwell temperatures (CRH), with Rate-Controlled Sintering (RCS) and with Two-Step Sintering (TSS). It was examined whether some of these three sintering schedules, with the same final density achieved, can lead to a decrease of the grain size of sintered ceramics. The results showed that only TSS (and only for selected materials) brought significant decrease of the grain size. .


1992 ◽  
Vol 296 ◽  
Author(s):  
J. J. Kingsley ◽  
L. R. Pederson

AbstractCombustion of a proper combination of an oxidizer and a fuel can produce the exothermicity required for the simultaneous synthesis of oxide ceramic powders. Oxidizers include metal nitrates, ammonium nitrate, and ammonium perchlorate, while urea, carbohydrazide, glycine and others have been used successfully as fuels. Combustion methods are particularly well-suited to producing multicomponent metal oxides, yielding compositionally homogeneous, fine particles with low impurity content. Organic fuels, particularly those containing nitrogen, also serve as a complexant in the precursor, which inhibits inhomogeneous precipitation from occurring prior to combustion. The exothermic redox decomposition of these oxidizer-fuel mixtures is initiated at low temperatures, usually <250°C. Properties of the products are influenced by the nature of the fuel and the oxidizer/fuel ratio. Many technologically important oxide ceramics have been produced by these methods.


Author(s):  
Karl Hauffe ◽  
Gundula Jänsch-Kaiser ◽  
David H. Sharp

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000152-000157 ◽  
Author(s):  
Satoko Tasaki ◽  
Naoki Komori ◽  
Soshu Kirihara

Porous oxide ceramics such as zinc oxide are applied for dye sensitized solar cell. This device requires consideration of high surface area, mechanical strengths and porous networks. Thus, we focused on the dendrite structures constructed from micrometer order rods with coordination numbers of 4, 8, and 12. There perfectly controlled structures were fabricated by stereolithography. Variations of the aspect ratios (lattice length to diameter ratios) were adjusted to control the porosity in the range 50–80 vol. % by using computer graphic software. The dendrite models sliced into a series of cross sectional patterns with uniform thickness by using a stereolithographic file format convertor. These numerical data were transferred into the micro processing equipment. High viscosity slurry material was prepared by mixing oxide ceramic powder and photosensitive acrylic resin. This slurry was spread on a flat stage and smoothed. An ultraviolet laser beam was exposed over the deposited layer to create cross-sectional planes. Through layer-by-layer processes, solid components were fabricated. These precursors were dewaxed at 600°C for 2 h at a heating rate of 1.0°C/min and sintered at 1400°C for 2 h at a heating rate of 5.0°C/min in air. The oxide ceramics microstructure was observed using a scanning electron microscope.


Author(s):  
Lothar Hasenberg ◽  
Roman Bender

Author(s):  
Peter Drodten ◽  
Dietmar Schedlitzky ◽  
Roman Bender

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