Quantitative assessment of microstructure and its effects on compression behavior of aluminum foams via high-resolution synchrotron X-ray tomography
Quantitative assessment of microstructure and its effects on compression behavior of aluminum foams via high-resolution synchrotron X-ray tomography
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DOI：
10.1007/s11661-006-1072-0
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发表时间：
2006-04
期刊：
影响因子：
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通讯作者：
H. Toda;T. Ohgaki;K. Uesugi;M. Kobayashi;K. Kuroda;T. Kobayashi;M. Niinomi;T. Akahori;
中科院分区：
文献类型：
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作者：
H. Toda;T. Ohgaki;K. Uesugi;M. Kobayashi;K. Kuroda;T. Kobayashi;M. Niinomi;T. Akahori;
同步加速器 X 射线显微断层扫描已用于泡沫铝细胞壁微观结构的三维表征。高分辨率相衬成像技术和多种应用技术的结合使得能够对微观结构进行定量图像分析以及评估其对变形行为的影响。应用技术包括局部断层扫描、微观结构测量和使用专门设计的材料试验台进行现场观察。已经阐明的是，在纯泡沫铝的情况下，无论任何微观结构因素如何，都会发生泡孔壁的延性屈曲，而在与锌和镁合金化的泡沫铝的情况下，由于粗微孔的存在及其分布与金属间颗粒和晶界无关而引起泡孔壁的脆性断裂。还证实，粗的 TiH2 颗粒（添加到合金熔体中的残留发泡剂）在变形过程中保持完整。然而，当发泡过程中的冷却速率较高时，较低的能量吸收可能归因于大量残留的 TiH2 颗粒及其不均匀分布。这些趋势也通过跟踪内部微观结构特征的三维应变图得到了证实。
Synchrotron X-ray microtomography has been used for the three-dimensional characterization of microstructure in the cell walls of aluminum foams. A combination of high-resolution phase contrast imaging technique and several application techniques has enabled the quantitative image analyses of microstructures as well as the assessment of their effects on deformation behaviors. The application techniques include local area tomography, microstructural gauging andin-situobservation using a specially designed material test rig. It has been clarified that ductile buckling of a cell wall occurs regardless of any of the microstructural factors in the case of a pure aluminum foam, while rather brittle fracture of a cell wall is induced by the existence of coarse micropores and their distribution independently of the intermetallic particles and the grain boundary in the case of aluminum foams alloyed with Zn and Mg. It has also been confirmed that coarse TiH2particles, which are a residual foaming agent added to alloy melts, remain intact during the deformation. When cooling rate during foaming is high, however, lower energy absorption might be attributable to the significant amount of residual TiH2particle and its inhomogeneous distribution. These tendencies are also confirmed by three-dimensional strain mapping by tracking internal microstructural features.