Effect of CeO₂ on low temperature pressureless sintering of porous Si₃N₄ ceramics

详细信息    查看全文

• 作者：Tiantian LIU (刘甜甜)^a ; ^b ; Cuifeng JIANG (姜翠凤)^a ; Wei GUO (郭 伟)^a ; ^{guowei68550@163.com}
• 关键词：CeO2 ; rice husk ; porous silicon nitride ceramics ; pressureless sintering ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：35
• 期：2
• 页码：172-176
• 全文大小：1535 K
• 卷排序：35

文摘

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 °C, 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 °C and CeO2 concentration was 5%, large elongated β-Si3N4 grains were well developed.