Densification behavior, microstructure, mechanical and optical properties of Mg-doped sialon with fluoride additives

详细信息    查看全文

• 作者：Zhangfu Yang^a ; ^{yangzhangfu77@aliyun.com} ; Bin Wang^b ; Yajun Ren^a ; Yin Liu^a ; Qinglin Shang^c ; Yong Yang^c ; Xin Liu^b ; Hao Wang^b ;
• 关键词：Sialon ; Densification ; Microstructure ; Mechanical properties ; Optical properties
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：May 2017
• 年：2017
• 卷：37
• 期：5
• 页码：1985-1992
• 全文大小：3028 K
• 卷排序：37

文摘

Mg-doped sialon ceramics with the composition of M0.4Si10.2Al1.8O1N15 were fully densified by hot pressing at 1850 °C for 1 h, using 0.5 wt.% MgF2 or CaF2 as a sintering additive. Densification behavior, phase assemblage, microstructure, and mechanical and optical properties were investigated in detail. The addition of fluorides, especially MgF2, not only resulted in more high-temperature liquid by promoting the dissolution of more N and other constituents but also reduced the viscosity of liquid due to the terminal effect of fluorine. Consequently, the densification was effectively improved. Additionally, the fluoride addition facilitated the formation of a small amount of β-sialon. Both the samples possessed high hardness (∼20 GPa) and fracture toughness (∼4.2 MPa m1/2). The CaF2-added sample exhibited higher infrared transmittance than its counterpart due to less residual glass phase. The present work implies that fluorides are also very effective sintering additives for densifying α-sialon.