Analysis Of The Mechanism Of Ductile Crack Initiation In High Densely Sintered Iron – Visualization And Quantification Of The 3D Pore-configurations By Synchrotron X-ray Tomography And Persistent Homology

Authors:

Koji Nakamura (Kyushu University, Japan),
Isshin Ando (Kyushu University, Japan),
Masatoshi Aramaki (Kyushu University, Japan),
Fei Jiang (Yamaguchi University, Japan),
Takeshi Tsuji (the University of Tokyo, Japan),
Kosuke Ashizuka (JFE Steel Co., Japan),
Masayuki Uesugi (Japan Synchrotron Radiation Research Institute (JASRI), Japan),
Akihisa Takeuchi (Japan Synchrotron Radiation Research Institute (JASRI), Japan),
Yukiko Ozaki (Kyushu University, Japan)

Abstract:

For a high-density pure iron sintered compact without open pores, the 3D pore configurations at different strain levels during ductility tests were visualized by X-ray computed tomography (CT). In addition, each three-dimensional structure was quantified as a two-dimensional scatter plot, persistent diagram, by 1st persistent homology (PH) analysis. By comparing the scatter plots, specific local pore configurations sensitive to changes in strain were extracted. The results showed that, just prior to fracture, adjacent closed pores formed pore-clusters and coalesce to each other into larger pores. This process is consistent with the theory of ductile fracture of the void model proposed for wrought metals.

DOI:

https://doi.org/10.59499/WP225372227