Effect of composition on phase assemblage,microstructure, mechanical and optical properties of Mg-doped sialon |
| |
Affiliation: | 1. Composite Engineering Research Center, Malek Ashtar University, Tehran, Iran;2. Faculty of Materials Engineering, Sahand University of Technology, Tabriz, Iran |
| |
Abstract: | Mg-doped sialon (Mgm/2Si12?m?nAlm+nOnN16?n) ceramics with different compositions of m = 2n = 0.6, 0.84, 1.0, 1.2, 1.6 were hot pressed at 1850 °C for 1 h. Phase assemblage, microstructure, mechanical and optical properties of these samples were investigated. All samples achieved/approached full densification. However, the densification of Mg-doped sialon ceramics with higher MgO/AlN content becomes more difficult. Additionally, the anisotropic growth of β-sialon grains was significantly inhibited. The unique characteristics of Mg-doped sialon ceramics intrinsically derive from the formation of Mg-containing AlN polytypoids, which consumed most of the high-temperature liquid. Furthermore, their high stability at high temperatures accounts for the difficulty in preparing single-phase Mg-α-sialon., The hardness of these samples gradually increases while indentation fracture toughness gradually decreases with increasing m = 2n value. Due to little residual glassy phase, high infrared transparency/translucency was more readily achieved in Mg-doped sialon. The m = 1.2 sample possesses the maximum transmittance of ~50% at ~2 μm. |
| |
Keywords: | Sialon Sintering Microstructure Optical properties Mechanical properties |
本文献已被 ScienceDirect 等数据库收录! |
|