Volume 32, Issue 1 (Jun 2013)                   jame 2013, 32(1): 79-89 | Back to browse issues page

XML Persian Abstract Print

Department of Materials and Metallurgical Engineering, Iran University of Science and Technology , n83.miadi@gmail.com
Abstract:   (5455 Views)
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).
Full-Text [PDF 542 kb]   (1006 Downloads)    
Type of Study: Research | Subject: General
Received: 2015/02/9 | Accepted: 2015/05/6 | Published: 2015/05/6