Ceramic dental materials have been considered as alternatives to metals for dental implants application. In this respect, zirconia tetragonal stabilized with %3 yttrium, is of great importance among the ceramic materials for endosseous dental implant application. Because of its good mechanical properties and color similar to tooth. The aim and novelty of this study was to design and prepare Y-T...

The synthesis of thioethers starting from alcohols and thiols in the presence of amorphous solid acid catalysts is reported. A silica alumina catalyst with a very low content in alumina gave excellent results in terms of both activity and selectivity also under solvent-free conditions. The reaction rate follows the electron density of the carbinol atom in the substrate alcohol and yields up to ...

Investigations of activation energy barriers for Al surface hopping on α-Al2O3 (0001) surfaces have been carried out by means of first-principles density functional theory calculations and the nudged elastic band method. Results show that surface diffusion on the (most stable) Al-terminated surface is relatively fast with an energy barrier of 0.75 eV, whereas Al hopping on the O-terminated surf...

Nowadays, magnesia carbon refractories are very important for the iron and steel industries. It is due to their unique properties, such as low wet ability with melt iron and steel. Therefore, it is important to extend the life of the refractory. In this research, the effect of calcined alumina and nano carbon on mechanical strength and corrosion resistance against slag in magnesia carbon refrac...

nowadays, magnesia carbon refractories are very important for the iron and steel industries. it is dueto their unique properties, such as low wet ability with melt iron and steel. therefore, it is importantto extend the life of the refractory. in this research, the effect of calcined alumina and nano carbon onmechanical strength and corrosion resistance against slag in magnesia carbon refractor...

Alumina composites containing in-situ-formed hexaluminate (LaAl,,018, LaMgAl,,O,,, SrAl12019, and Mg,NaAl,,O,) platelets can be pressureless-sintered to high density. The grain morphology of the aluminates can be controlled by composition. A peak toughness 50% higher than that of alumina is obtained at 30 vol% aluminates, with a modest reduction (10%) in hardness and Young’s modulus. Although c...

In this paper, a wax-based binder was developed for low-pressure injection molding of very fine (0,4 μm) average particle size alumina ceramic bodies. The major component used in the binder mixture was paraffin wax. The process of binder removal from the green ceramics presented several difficulties especially when the ceramic powder was very fine, and the pieces had large cross-section. The pr...

Sintering of green samples of alumina produced by ice-templating was followed in situ in an environmental scanning electron microscope (ESEM) up to temperatures as high as 1375°C. These alumina samples with well-defined architectures are of great interest in the field of materials science due to their high specific strength (especially in compression), low density and adaptable porosity. For th...

Bi-continuous alumina/aluminium composites were made by infiltrating an alumina preform which had the structure of a reticulated ceramic foam. The low density preforms were prepared from a polyurethane suspension of alumina powder which was pyrolysed and sintered after foaming. Higher density preforms consisted of ceramic foams with open cells. All these preforms were infiltrated with 6061 alum...