Microstructural Evaluation of Deformation Mechanisms in Silicon Nitride Ceramics
Microstructural Evaluation of Deformation Mechanisms in Silicon Nitride Ceramics
复制标题
氮化硅陶瓷变形机制的微观结构评估
DOI：
10.1002/9780470314821.ch40
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
A. Mukherjee
中科院分区：
文献类型：
--
作者：
J. Schneider;A. Mukherjee
研究了氮化硅（Si3N4）在压缩变形前后的相组成和形貌变化。采用不同的粘度添加剂，采用快速凝固技术获得不同α相含量和晶粒形貌的试样。低粘度添加剂体系中的相变发生在致密化之前，产生了细长的微观结构，其优选取向在棱柱[210]方向上。有限的变形与这种晶粒形态相适应，这表明n=1的流动应力依赖性。高粘度添加剂体系中的致密化发生在相变产生等轴微观结构，几乎没有优先取向。增强的变形被容纳在这种晶粒形态与所示的流动应力依赖性n=2。透射电子显微镜（TEM）照片对应于X射线衍射（XRD）分析的晶粒形态。选区衍射（SAD）用于验证相位。
Changes of phase composition and morphology were investigated in silicon nitride (Si3N4) before and after compressive deformation testing. Using different viscosity additives, rapid consolidation techniques were used to achieve specimens with different α-phase content and grain morphology. Low viscosity additive systems in which the phase change occurred before densification produced elongated microstructure with preferred orientation noted in the prismatic [210] direction. Limited deformation was accommodated with this grain morphology which indicated a flow stress dependency of n=1. High viscosity additive systems in which the densification occurred before the phase change produced equiaxed microstructures with virtually no preferred orientation. Enhanced deformation was accommodated in this grain morphology with an indicated flow stress dependency of n=2. Transmission electron microscope (TEM) photographs corresponded with x-ray diffraction (XRD) analysis for the grain morphology. Selected area diffraction (SAD) was used to verify phases.