12/3(一)專題演講公告

20181203- Seiichiro Ii

演講人Seiichiro Ii 博士

服務單位日本國立研究開發法人物質.材料研究機構 (National Institute for Materials Science, NIMS)

演講題目Advantages of In-Situ TEM Technique for Materials Dynamics

演講時間107123(星期一)早上1020

演講地點工綜館203國際演講廳

演講摘要

Understanding of dynamics of the materials behavior such as phase transformation, dislocation motion, fracture and so on, in-situ observation is one of powerful techniques. In this talk, I would like to introduce about past and current situation and the advantages of the in-situ TEM studies with our studies.

For example, crack propagation behavior in brittle ceramic materials is scientific and technological important, since the crack propagation determines fracture toughness and reliability of the materials. It can be expected that the crack propagation takes place by breaking individual atomic bonds in grain interior or grain boundaries, which will result in the formation of atomically-flat fractured surfaces and atomically sharp crack tips. Many of the experiments for the crack propagation behavior have been made for the specimens after crack generation. In other words, ex-situ experiments have been done. In ceramic materials, transmission electron microscopy (TEM) specimens have been prepared by ion-milling technique, so that the atomic structure around crack surface is changed during sample preparation process. [1-4]

Dislocation motion during plastic deformation in metals is also given in this seminar.

References

[1] S. Ii et al., Philos. Mag., 84, 2767 (2004)

[2] S. Ii et al., Appl. Sur. Sci., 241, 68 (2005)

[3] P. F. Becher et al., J. Am. Ceram. Soc., 88, 1222 (2005)

[4] S. Ii et al., J. Electron Microscopy, 53, 121 (2004)

20181203