Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10626093 | Ceramics International | 2013 | 7 Pages |
Abstract
The optical properties and microwave dielectric properties of transparent polycrystalline MgAl2O4 ceramics sintered by spark plasma sintering (SPS) through homemade nanosized MgAl2O4 powders at temperatures between 1250 °C and 1375 °C are discussed. The results indicate that, with increasing sintering temperatures, grain growth and densification occurred up to 1275 °C, and above 1350 °C, rapid grain and pore growth occurred. The in-line light transmission increases with the densification and decreases with the grain/pore growth, which can be as high as 70% at the wavelength of 550 nm and 82% at the wavelength of 2000 nm, respectively. As the sintering temperature increases, QÃf and dielectric constant εr values increase to maximum and then decrease respectively, while Ïf value is almost independent of the sintering temperatures and remains between â77 and â71 ppm/°C. The optimal microwave dielectric properties (εr=8.38, QÃf=54,000 GHz and Ïf=â74 ppm/°C) are achieved for transparent MgAl2O4 ceramics produced by spark plasma sintering at 1325 °C for 20 min.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Ping Fu, Wenzhong Lu, Wen Lei, Yong Xu, Xuehua Wang, Jiamin Wu,