This work demonstrates that large pores promote abnormal grain growth, a commonly observed but poorly understood behavior. To investigate this phenomenon, calcia doped aluminum oxide is used as a model ceramic because of its known propensity for abnormal grain growth. Controlled porous microstructures are fabricated using polymer microspheres with nominal diameters approximately an order of magnitude larger than the average grain diameters. Electron backscattered diffraction maps indicate that the introduction of large pores (∼3 vol.%) promotes abnormal grain growth, increasing the total abnormal grain area by more than 60 % when sintered at 1600 °C for 4 h in air. The differences between samples with and without large pores provide insight into the initiation of abnormal grain growth, which is needed to predict microstructure evolution in complex systems with such defects.

中文翻译：

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大孔隙促进氧化钙掺杂氧化铝中的异常晶粒生长行为

这项工作表明，大孔隙会促进异常晶粒生长，这是一种常见但人们知之甚少的行为。为了研究这种现象，使用氧化钙掺杂的氧化铝作为模型陶瓷，因为它具有异常晶粒生长的已知倾向。受控多孔微结构是使用标称直径比平均粒径大大约一个数量级的聚合物微球制造的。电子背散射衍射图表明，大孔隙（∼3 vol.%）的引入促进了异常晶粒生长，在空气中于 1600 °C 下烧结 4 小时时，异常晶粒总面积增加了 60% 以上。具有和不具有大孔隙的样品之间的差异可以深入了解异常晶粒生长的开始，这对于预测具有此类缺陷的复杂系统中的微观结构演变是必要的。