Effect of CeO2 on low temperature pressureless sintering of porous Si3N4 ceramics
来源期刊：Journal of Rare Earths2017年第2期
论文作者：刘甜甜 姜翠凤 郭伟
文章页码：172 - 176
摘 要：Porous silicon nitride（Si3N4） ceramics were fabricated by low temperature pressureless sintering, using carbonized rice husk and α-Si3N4 powders as raw materials, and MgO-CeO2 as sintering additives. The effects of CeO2 concentration and sintering temperature on phase composition, microstructure, porosity and flexural strength of the sintered products were investigated by X-ray diffraction（XRD）, scanning electronic microscopy（SEM）, Archimedes’ displacement method and three-point bending strength, respectively. The results suggested that MgO-CeO2 was a much more effective sintering additive for Si3N4 than MgO alone. When CeO2 concentration was 4 wt.%–5 wt.% and sintering temperatures were in a range of 1500 to 1550 oC, the obtained porous silicon nitride ceramics had the porosity of 45.78%–42.81% and flexural strength of 49.44–84.09 MPa. Moreover, when sintering temperature was 1550 oC and CeO2 concentration was 5%, large elongated β-Si3N4 grains were well developed.
刘甜甜1,2，姜翠凤1，郭伟1
1. School of Materials Engineering, Yancheng Institute of Technology2. School of Materials Science and Engineering, Anhui University of Science and Technology
摘 要：Porous silicon nitride（Si3N4） ceramics were fabricated by low temperature pressureless sintering, using carbonized rice husk and α-Si3N4 powders as raw materials, and MgO-CeO2 as sintering additives. The effects of CeO2 concentration and sintering temperature on phase composition, microstructure, porosity and flexural strength of the sintered products were investigated by X-ray diffraction（XRD）, scanning electronic microscopy（SEM）, Archimedes’ displacement method and three-point bending strength, respectively. The results suggested that MgO-CeO2 was a much more effective sintering additive for Si3N4 than MgO alone. When CeO2 concentration was 4 wt.%–5 wt.% and sintering temperatures were in a range of 1500 to 1550 oC, the obtained porous silicon nitride ceramics had the porosity of 45.78%–42.81% and flexural strength of 49.44–84.09 MPa. Moreover, when sintering temperature was 1550 oC and CeO2 concentration was 5%, large elongated β-Si3N4 grains were well developed.
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