nMicrostructure of a thin cast Al-Fe-Mn-Si strip

The recent trend in Twin Roll Casting has been to reduce the casting gauge to less than 3 mm in order to reduce the processing costs, to take advantage of increasing rates of solidification and to increase productivity. Conventional casters typically cast strips 6 to 10 mm thick and operate at essentially constant production rates in this range. The new generation casters, on the other hand, are able to cast strips down to 1 mm and offer a notable increase in the casting speed and thus in the caster productivity. It has been reported that the thin strips show some marked differences with respect to conventional strips owing to the temperature gradients and deformation involved in the thin-gauge casting process and may require different down stream processing cycles. The characterization of the thin strip structure is thus essential. This paper describes the microstructure of a thin-cast (3 mm) Al-Fe-Mn-Si (AA8006) strip in comparison with another strip of the same alloy cast at conventional gauge (6 mm).