Twin-roll casting (TRC) is an advantageous substitution for Direct-Chill (DC) casting in
the manufacturing of rolled aluminium products. The results of a study of the phase transformations
and their interaction with recrystallization occurring during the annealing of TRC Al-Mn based alloys
are reported. Four alloys with different contents of Mn, Si and Fe were investigated. Precipitation was
studied by resistometric measurements in the course of a heating at linear rate. The microstructural
processes responsible for the observed changes in resistivity were identified by TEM examinations of
quenched specimens. The changes in the microstructure and solute content during homogenisations at
450°C and 610°C were monitored by conductivity and hardness measurements and polarised light
microscopy. It was elucidated that the temperature and kinetics of phase transformations are
influenced not only by the content of Mn, but also by Si content. In alloys with low Si content, the
decomposition of solid solution and the transformation of primary phases occur in much larger
temperature range than in the alloys with high Si content. The precipitation of Mn and Si, concurrent
to recrystallization, was observed to retard the latter, especially in alloys with high Mn and Si content.
Analysis of defects in a twin roll cast
Mg‐Y‐Zn
magnesium alloy
