Semisolid Strip Casting Using a Vertical Type Twin Roll Caster

摘要

Semisolid strip casting of A356 alloy was tried using a vertical type twin roll caster equipped with a nozzle and a cooling slope. Molten metal was poured on the cooling slope and the molten metal became semisolid slurry. Solidification rate of the semisolid slurry was lower than 5%. Low solidification rate roll casting was carried out. Roll speed was from 60 m/min to 180 m/min. Strip thickness, which was thinner than 3mm, could be cast. Microstructure was not columnar but equiaxed structure. Eutectic Si became very fine and globular. Ductility of the strip after homogenization was enough for cold rolling. The strip could be cold rolled until 0.5 mm. Mechanical properties were investigated after homogenization, cold rolling and T6 heat treatment. The elongation was improved and better than 15%. The strip, that thickness was 0.5 mm and was annealed, was not broken after 180 degrees bending.