LAUSR

Abstract The influence of radial convection on the microstructure development has been investigated in directionally solidified Sn-36at.%Ni peritectic alloys at a constant growth velocity with different sample diameters. Since the rejected Sn is denser than Ni, there existed no axial convection in directionally solidified Sn-36at.%Ni peritectic alloys, however, the radial convection still influenced the microstructures. It was demonstrated through the dendrite tip radius R that the diffusive growth condition could be obtained in this alloy when the sample diameter was reduced to 1 mm. Furthermore, it was confirmed that the radial convection could obviously promote the peritectic transformation process in Sn-Ni peritectic alloy.