Effect of melt heat treatment on the solid/liquid interface morphology of directional solidification

A set of quadral-electrode DC input voltage measure equipment was built up to detect the electrical resistance of Sb–Bi single-phase alloy. The results suggest that Sb–5%wt Bi undergoes structural transition in the temperature range of 730–750°C. By overheating the melt to different temperatures and then cooling to 690°C after a period of time, the samples are directionally solidified in a Bridgeman-type furnace. It is found for the first time that after heat treatment of the melt, the solid/liquid interface morphology shows significant variation depending on the speciic heat treatment. Also, in Ag–Cu, Al–Cu systems, bicrystal growth with different orientation is found to have different interface morphologies after heat treatment. It is believed that the evolution of the cluster size distribution in the melt contributes to these phenomena.