The effect of melt superheat on interface morphological stability during directional solidification

The influences of hysteresis and relaxation of melt superheat on the morphological stability of interface in directional solidification were described. During relaxation of melt structure the viscosity eta decreases, but solute distribution k and concentration gradient in liquid increase. When superheating temperature T+, is lower than the critical superheating temperature T-+(c), eta decreases and k increases with increasing of T+ which increases the planer interface stability. When superheating temperature T+ is higher than the temperature T-+(c), with T+ increasing the concentration gradient in liquid increases significantly, which decreases the planer interface stability.