Bimodal Microstructure in Silicon Nitride–Barium Aluminum Silicate Ceramic‐Matrix Composites by Pressureless Sintering
Bimodal Microstructure in Silicon Nitride–Barium Aluminum Silicate Ceramic‐Matrix Composites by Pressureless Sintering
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无压烧结氮化硅-硅酸铝钡陶瓷基复合材料的双峰微观结构
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发表时间：
2004
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通讯作者：
K. White
中科院分区：
文献类型：
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作者：
Yi Fang;F. Yu;K. White
A distinct bimodal microstructure has been obtained in a Si3N4–BAS (barium aluminum silicate) ceramic-matrix composite by pressureless sintering. It is shown that the addition of coarse β-Si3N4 seeds causes abnormal grain growth in this composite, and hence encourages the formation of a bimodal microstructure. This abnormal grain growth is due to the nature of the heterogeneous nucleation mechanism in Si3N4α-to-β phase transformation, and is promoted by the transformation. After complete phase transformation, further abnormal grain growth is comparably slow and governed by the Ostwald ripening mechanism. Therefore, a stable bimodal microstructure can be easily achieved by pressureless sintering.
