In-Situ Observation of Dendrite Growth during Solidification of Al-10wt.％Cu Alloy under Pulsed Magnetic Field

摘要

Time-resolved X-ray imaging with intense,high brightness and monochromatic third-generation synchrotron radiation,and a high-resolution fast-readout charge coupled device(CCD)system have been used to in-situ observe the dendrite growth of a solidifying Al-10wt.％Cu alloy under pulsed magnetic field.The imaging results indicate that the secondary dendrite tip growth underwent a rapid deceleration once the pulsed magnetic field was applied.The remelting phenomenon of small dendrites was also observed when applying the pulsed magnetic field at the beginning of solidification.This is related to the Joule heat effect caused by the imposed pulsed magnetic field.Whilst,fragmentation of the dendrites usually caused by the forced convection induced by pulsed magnetic field was not found in the present work.