IROAST Visiting Professor Pavel Lejček from the Institute of Physics, Academy of Sciences of the Czech Republic gave a talk at the 39th IROAST Seminar on November 7, 2018. The seminar was organized by Professor Sadahiro Tsurekawa from the Faculty of Advanced Science and Technology (FAST). Professor Lejček introduced his university and talked about his research into the “Fundamentals of grain boundary segregation and related phenomena.”

Prof.Tsurekawa

Prof. Lejček

November 7 (Wed.), 2018: 39th IROAST Seminar －Fundamentals of grain boundary segregation and related phenomena

IROAST will hold the 39th IROAST Seminar. Please see the poster and abstract below. We hope to see you at the seminar.

<Abstract>
Grain boundaries are important components of the structure in polycrystalline materials, which seriously affect the properties of the parts used in applications. One of the important phenomena affecting this behavior is their chemical composition, which differs from that of the grain interior, i.e., grain boundary segregation. The seriousness of this phenomenon can be demonstrated by the fact that extended segregation changes the bonds at the grain boundaries and consequently their cohesion, which can result in quick intergranular brittle fracture. On the other hand, solute atoms accumulated at the grain boundaries reduce their mobility thus stabilizing the structure of nanocrystalline materials.

In this lecture, fundamentals of the grain boundary segregation will be presented. After short description and classification of grain boundaries, the methods to study the grain boundary segregation will be shown. Further, basic segregation isotherms will be derived and effect of various parameters influencing the chemical composition of the grain boundaries will be discussed. Finally, the relationship between grain boundary segregation and other materials phenomena will be mentioned.