Effect of composition on phase assemblage, microstructure, mechanical and optical properties of Mg-doped sialon

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• 作者：Zhangfu Yang^a ; ^{yangzhangfu77@aliyun.com" class="auth_mail" title="E-mail the corresponding author} ; Qinglin Shang^b ; Xinyi Shen^a ; Liqiang Zhang^a ; Junshan Gao^a ; Hao Wang^c ; ^{shswangh@whut.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Sialon ; Sintering ; Microstructure ; Optical properties ; Mechanical properties
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：37
• 期：1
• 页码：91-98
• 全文大小：2041 K

文摘

Mg-doped sialon (Mg_m/2Si_12−m−nAl_m+nO_nN_16−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.