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Al2O3 Ceramics (al2o3 + ceramics)

Distribution by Scientific Domains
Polymers and Materials Science83%

Selected Abstracts

Microfabrication of Three-Dimensional Photonic Crystals of SiO2,Al2O3 Ceramics and Their Terahertz Wave Properties

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2008
Weiwu Chen
Dense three-dimensional microphotonic crystals of SiO2,Al2O3 ceramics were fabricated using microstereolithography and successive sintering process. The forming dimensional tolerance for a 50 vol% ceramic paste is 10 ,m and sintering shrinkage is around 12%. Diamond-type photonic crystals with lattice constants of 500 and 125 ,m were formed and sintered successfully. The band gaps of the samples were measured and compared with the theoretically calculated band diagram. [source]

Novel Synthetic Route to Biomorphic Al2O3 Ceramics.

CHEMINFORM, Issue 26 2005
Carlos R. Rambo
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Microfabrication of Three-Dimensional Photonic Crystals of SiO2,Al2O3 Ceramics and Their Terahertz Wave Properties

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2008
Weiwu Chen
Dense three-dimensional microphotonic crystals of SiO2,Al2O3 ceramics were fabricated using microstereolithography and successive sintering process. The forming dimensional tolerance for a 50 vol% ceramic paste is 10 ,m and sintering shrinkage is around 12%. Diamond-type photonic crystals with lattice constants of 500 and 125 ,m were formed and sintered successfully. The band gaps of the samples were measured and compared with the theoretically calculated band diagram. [source]

Effect of Oligosaccharide Alcohol Addition to Alumina Slurry and Translucent Alumina Produced by Slip Casting

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2003
Yuji Hotta
A slurry used to produce dense green compacts by slip casting should exhibit low viscosity, high solids content, and good dispersion. Slurries with good characteristics were produced in the present study by adding oligosaccharide alcohol to an Al2O3 slurry with an NH4+ salt of poly(methacrylic acid) (NH4+ -PMA). The role of NH4+ -PMA and oligosaccharide alcohol in the Al2O3 slurry was examined by DTA, ,-potential measurement, high-pressure liquid chromatography, and viscometry. The viscosity of the slurry with NH4+ -PMA and oligosaccharide alcohol was lower than that of the slurry with NH4+ -PMA at a high solids content. Oligosaccharide alcohol did not interact with the Al2O3 surface. However, the Al2O3 slurry with NH4+ -PMA was influenced by the addition of oligosaccharide alcohol. We found that the dispersibility of the slurry was greatly improved by adding oligosaccharide alcohol. The transmittance of the Al2O3 ceramics produced by slip casting using the slurry with both NH4+ -PMA and oligosaccharide alcohol was higher than that of ceramics produced by slip casting using the slurry with NH4+ -PMA alone. The increased optical property resulted from low viscosity, which was attributed to the addition of oligosaccharide alcohol, at a high solids content. [source]

Transparent Sintered Corundum with High Hardness and Strength

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2003
Andreas Krell
Commercial corundum powder and a liquid-shaping approach are used for manufacturing complex hollow components and large flat windows of sintered and hot isostatically pressed Al2O3 ceramics having grain sizes of 0.4,0.6 ,m at relative densities of >99.9%. High macrohardness (HV10 = 20,21 GPa) and four-point bending strength (600,700 MPa; 750,900 MPa in three-point bending) are associated with a real in-line transmission of 55%,65% through polished plates. The submicrometer microstructure and the optical properties can be retained for use at >1100°C using dopants that shift the sintering temperature to high values without additional grain growth. [source]

Sintering of Partially Stabilized Zirconia by Microwave Heating Using ZnO,MnO2,Al2O3 Plates in a Domestic Microwave Oven

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2000
Satoru Fujitsu
Partially stabilized zirconia (PSZ) powders were fully densified by microwave heating using a domestic microwave oven. Pressed powder compacts of PSZ were sandwiched between two ZnO,MnO2,Al2O3 ceramic plates and put into the microwave oven. In the first step, PSZ green pellets were heated by self-heating of ZnO,MnO2,Al2O3 ceramics (1000°C). In the second step, the heated PSZ pellets absorbed microwave energy and self-heated up to a higher temperature (1250°C), leading to densification. The density of PSZ obtained by heating in the microwave oven for 16 min was 5.7 g/cm3, which was approximately equal to the density of bodies sintered at 1300°C for 4 h or 1400°C for 16 min by the conventional method. The average grain size of the sample obtained by this method was larger than the average grain size of samples sintered by the conventional method with a similar heating process. [source]