The aim of this work is to study by X-Ray microtomography carried out at ESRF
Grenoble the microstructure of an Al-4wt%Cu alloy which was previously cold rolled to obtain
globules of the solid phase upon heating in the semi-solid range. Since this process produced
entrapped liquid in the globules, 3D quantification of this liquid was performed. Moreover, the
influence of the addition to the alloy of a small amount of Ba, which has been shown to decrease the
contiguity between the solid globules as a consequence of the decrease of the solid-liquid interfacial
energy σsl, was investigated. It is in particular shown that the amount of entrapped liquid is much
larger in the Ba-containing alloy in agreement with the reduction of σsl, whereas the size of the
liquid pockets is similar. In addition characterization of the interglobular liquid shows that the
interface area between this liquid and the solid per unit volume is larger for the alloys containing Ba
in agreement with previous observations carried out on 2D sections. The influence of strain during
cold rolling is also reported but it is shown to have a quite limited influence on the previous
parameters.
Characterization of Cu Distribution in an Al-0.3%Cu Alloy Cold Rolled to 98%