In situ study on solidification controlled by electric current pulse in Al-Bi immiscible alloy via synchrotron radiation imaging technology

摘要

The Bi-rich droplets motion in a solidifying Al-Bi immiscible alloy was in situ investigated using a synchrotron microradiography technique. The electric current pulse (ECP) was applied to control the droplets motion and distribution in the Al-matrix during solidification. Without ECP treatment, it was found that the second phase presented spherical droplets and distributed in the Al-matrix without obvious aggregation and segregation. With ECP treatment, the second phase seriously aggregated and formed lots of big clusters in the matrix. The electromagnetic pinch force induced by ECP was used to explain this phenomenon.