3D multiscale-imaging of processing-induced defects formed during sintering of hierarchical powder packings
3D multiscale-imaging of processing-induced defects formed during sintering of hierarchical powder packings
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DOI：
10.1038/s41598-019-48127-y
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发表时间：
2019-08-12
影响因子：
4.6
通讯作者：
Wakai, Fumihiro
中科院分区：
文献类型：
--
作者：
Okuma, Gaku;Watanabe, Shuhei;Wakai, Fumihiro
加工缺陷的表征是实现无缺陷加工的重要环节，对保证脆性陶瓷的结构可靠性具有重要意义。多尺度X射线计算机断层成像技术由宽场低分辨率的微CT和窄场高分辨率的纳米CT组成，适用于观察长度小、裂纹张开位移很小的裂纹类缺陷。在这里，我们应用这个强大的成像工具，以揭示复杂的三维形态的缺陷在烧结氧化铝。颗粒的分级堆积结构是几种类型的强度限制缺陷的起源，这些缺陷不能由于异质显微组织的差异烧结而消除。这种内部缺陷的成像技术为结构材料的开发提供了加工和断裂强度之间的联系。
The characterization of the processing-induced defects is an essential step for developing defect-free processing, which is important to the assurance of structural reliability of brittle ceramics. The multiscale X-ray computed tomography, consisting of micro-CT as a wide-field and low-resolution system and nano-CT as a narrow-field and high-resolution system, is suitable for observing crack-like defects with small length and with very small crack opening displacement. Here we applied this powerful imaging tool in order to reveal the complicated three-dimensional morphology of defects evolved during sintering of alumina. The hierarchical packing structure of granules was the origin of several types of strength-limiting defects, which could not be eliminated due to the differential sintering of heterogeneous microstructures. This imaging technique of internal defects provides a link between the processing and the fracture strength for the development of structural materials.