Showing 2 results for H. Sarpoolaky
N. Miadi, H. Sarpoolaky, H. Ghassai,
Volume 32, Issue 1 (Jun 2013)
Abstract
In this study, mullite– irconia composite samples were prepared by reaction sintering of alumina and zircon powder via gel casting process. Gel casting is a new ceramic forming technique. This process is based on the casting of slurry, containing ceramic powder, dispersant and premix monomer solution. To achieve stabilized, high solid loading (80 wt%) and castable slurry, the rheological properties of slurry were optimized. The monomers polymerized the slurry to form gelled specimens. After gelation, the specimens were unmolded, then dried out under controlled condition. Burning out and sintering of the specimens was carried out in the range of 1400-1700°C. Apparent porosity and bulk density of the sintered samples were measured by soaking in water. Crystalline phase evolution and microstructure were determined by XRD and SEM techniques. Results showed that the reaction sintering and mullite formation was completed at 1700°C due to very slow diffusion of Al3+ ions within amorphous silica formed at the decomposition of zircon. The sintered samples at this temperature also showed the lowest apparent porosity (≈ 4%) and the highest bulk density (≈3.40 gr/cm-3).
F. Hosseinzadeh, H. Sarpoolaky,
Volume 32, Issue 2 (Dec 2013)
Abstract
Refractory carbides are becoming a group of promising material due to their unique properties, such as high hardness, high wear and corrosion resistance, high thermal conductivity, high melting point, high strength even at high temperatures, and a high degree of chemical stability. Among these carbides, titanium carbide (TiC) is one of the most important engineering material, based on its promising properties. This paper presents a novel approach to preparing ultrafine TiC by sol–gel processing. This novel process would minimize kinetic barriers because carbon (coming from sucrose) was homogeneous dispersed in the precursor of TiO2 by sol–gel process. As a result, the increased contact area between reactants should make the reaction to complete at lower temperatures.
