The origin of ‘anomalous’ microsegregation in Al–Si foundry alloys—modelling and experimental verification

Slowly cooled Al–7 wt.% Si foundry alloys show ‘anomalous’ segregation of Si in the dendrite arms, with higher concentrations in the centre of the dendrites than near the eutectic. Calculations and experiments show that this is caused by growth of particles in the eutectic during the cooling period after solidification is completed.