Abstract Scope |
Due to high cooling rate, the direct chill cast ingot solidifies under a non-equilibrium solidification condition that results in the formation of non-equilibrium intermetallics. Some of the solidified intermetallics are brittle, coarser and have a lower melting point, hence complicating the downstream thermomechanical processes and affecting the final sheet properties such as toughness and corrosion. Therefore it is essential to control the intermetallic formation during casting. In the current study, we show the influence of jet stirring and in-situ homogenization on the formation of intermetallics during DC casting of a 6xxx Al alloy rolling ingot. In particular, the intermetallic phase content through the ingot thickness has been characterized using various microscopes, a differential scanning colorimeter and X-ray diffractometer. Phenol intermetallic extraction has been used to facilitate the three dimensional chemistry and volume fraction of intermetallics, with changes rationalized in terms of the effect of jet stirring and in-situ homogenization pre-treatment. |