Particle Coagulation in Molten Metal Based on Three-Dimensional Analysis of Cluster by X-Ray Micro-Computer Tomography (CT)

Abstract

Particle coagulation plays a key role in steel refining process to remove inclusions. Many research works focus on the behaviors of particle coagulation. To reveal its mechanism water model experiments have been performed by some researchers including the authors' group. In this paper, experiments of particle coagulation were carried out with molten Al including SiC particles in a mechanically agitated crucible with two baffles. Particle coagulation and formation of clusters were observed on the microscopy images of as-polished samples. Three-dimensional (3D) analysis of the clusters in solidified Al was implemented by X-ray micro CT available at SPring-8. The methods to distinguish clusters on two-dimensional (2D) cross-sectional images were discussed, which were established in the previous works by the present authors' group. The characteristics of the 3D SiC clusters and their 2D cross-sections were analyzed. The statistical ranges of the parameters for 2D clusters were used as criterions to distinguish the clusters on 2D microscopy images from the as-polished samples. The kinetics of SiC particle coagulation was studied by the measured cluster number density and size using our program to distinguish cluster in 2D crosssectional images according to 3D information (DC-2D-3D). The calculated and experimental results of the SiC particle coagulation in molten Al agree well with each other.

Three-dimensional Observation of Nonmetallic Inclusion Clusters in Solid Metal by X-ray Micro-CT

“…Tao LI, 1,2) * Shin-ichi SHIMASAKI, 1,3) Shoji TANIGUCHI, 1) Shunsuke NARITA 1,4) and Kentaro UESUGI 5) 1) Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aoba-yama, Aoba-ku, Sendai, 980-8579 Japan.…”

“…16) The current authors' group has applied the X-ray micro-CT to study the 3D structure of TiB 2 and SiC particle clusters in aluminium. 17,18) The coagulation of SiC particles in molten aluminum was studied based on the 3D observation of the particle clusters, 5) which attracted quite a lot interests from researchers. In this study, we disclose the details of the development of the 3D observation method for Al-TiB 2 and Al-SiC systems.…”

“…The 3D analysis of the inclusion cluster structure will provide significant information for understanding the mechanisms of inclusion behaviors in liquid metal, such as inclusion coagulation, flotation and bubble adhesion. Many modelling and experimental works [1][2][3][4][5] have been performed to investigate the inclusion behaviors by using spherical particles. Nevertheless, the morphology of the inclusions is far from spherical when they coagulate each other and grow up into clusters.…”

Comparison of Agglomeration Behavior of Fine Particles in Liquid among Various Mixing Operations

“…Many experimental and theoretical studies have been done on the agglomeration behavior of fine particles in liquid: agglomeration structure by using a fractal dimension, [6][7][8][9][10][11] wettability of particles, 12,13) heterogeneous agglomeration with a different surface electrification and size, [14][15][16][17][18] particle collision frequency in turbulent flow, 19,20) particle-size grouping.…”

Reliability of Inclusion Statistics in Steel by Stereological Methods

“…The cleanliness steel is a relative concept which has been greatly improved by the progress of steel refining techniques and equipment employing inclusion coagulation and bubble flotation. [4][5][6][7][8][9] To evaluate the steel refining techniques, it is critical to estimate the number density and the size distribution of the inclusion is steel samples.…”