Characterization of dendritic growth in Fe_C system using time-resolved X-ray tomography and physics-based filtering

Joint 5th International Conference on Advances in Solidification Processes;5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining

土木建筑工程;计算机科学

Yasuda, H.^1 ; Kawarasaki, T.^1 ; Tomiyori, Y.^1 ; Kato, Y.^1 ; Morishita, K.^2

Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto

606-8501, Japan^1

Department of Materials Science and Engineering, Kyushu University, Nishi-ku, Fukuoka

819-0395, Japan^2

关键词: Computed tomography images;    Interface curvatures;    Low contrast resolution;    Model and simulation;    Solid/liquid interfaces;    Synchrotron radiation facility;    Synchrotron radiation x-rays;    Three dimensional images;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/529/1/012023/pdf
DOI  :  10.1088/1757-899X/529/1/012023

来源: IOP

【 摘 要 】

Time-resolved in situ tomography of dendritic growth in Fe-0.45 mass% C carbon steel was performed using synchrotron radiation X-rays at SPring-8 synchrotron radiation facility (Japan) with improvement of the image quality using a physics-based filter. The voxel size of the reconstructed image was approximately 6.5 μm × 6.5 μm × 6.5 μm, and the time resolution (duration of 360° rotation) was 4 s (0.25 rps). Three-dimensional images of the dendrites were reconstructed even without image processing; however, the low contrast resolution in Fe-C alloys led to poor image quality. Consequently, it was impossible to precisely track the solid/liquid interface or evaluate the average curvature. To improve the image quality, a physics-based filter (a PF filter) was developed using a phase-field model. In the PF filter, images were retrieved in terms of interface curvature. The PF filter significantly improved the computed tomography image quality. As a result, dendritic growth was clearly observed even in Fe-C alloys. Moreover, the average curvature of the solid/liquid interface was evaluated as a function of solidification time (solid fraction). The ability to systematically characterize growing dendrites will be beneficial for modeling and simulation of solidification phenomena.