Melt Conditioning Twin Roll Casting with Thermo-Mechanical Treatment of Recycled AA6111 Alloy

Abstract

A high shear melt conditioning twin roll casting process with thermo-mechanical treatment was tested to increase the tolerance to high impurity levels in recycled aluminium alloy. Applying high shear melt conditioning prior to casting of recycled AA6111 alloy exhibits reduced centre-line segregation and a fine equiaxed grain structure with improved sheet quality. Homogenisation at 540°C for 8 h with annealing at 520°C for 10 min of the melt-conditioned twin roll casting strip (MC-TRC) showed a clear grain recrystallisation, which was better than the conventional twin roll casting TRC strip. The mechanical test showed a significant improvement in the hardness after applying high shear melt conditioning with thermo-mechanical treatment.