Effect of a high magnetic field on the morphology of the primary dendrite in directionally solidified Pb-25 at% Bi peritectic alloy

•The magnetic field caused the irregularity and break of the primary dendrite.•The magnetic field increased the primary dendrite spacing.•The Seebeck voltage near the liquid–solid interface was measured.

Effect of a high magnetic field on the morphology of the primary dendrite in directionally solidified Pb-25 at% Bi peritectic alloy was investigated experimentally. Results indicated that the high magnetic field caused the irregularity and break of the primary dendrite. As the applied magnetic field increased, the primary dendritic spacing increased. Further, the Seebeck voltage near the liquid–solid interface was measured at various growth speeds. It was found that the Seebeck voltage decreased as the growth speed increased. The above results may be attributed to the thermoelectric magnetic force (TEMF) imposed on the solid. The primary dendrite fragments, surrounded by the peritectic phase, which is associated with the increase of the dendritic spacing.