Directional solidification velocity of undercooled Cu70Ni30 alloy melt

The directional dendrite growth velocity in the Cu70Ni30 alloy melt underco oled by 90 similar to 185 K was measured by high speed cinematography, and compared with the calculated free dendrite growth velocity. It was found th at at lower undercoolings the interaction between the adjacent directionall y growing dendrites is weak, and there is not marked difference between the velocity of the directionally growing dendrite and that of free dendrite. But with undercooling increasing, the interaction is enhanced due to the de crease of the primary arm spacing, which makes the velocity difference enla rges quickly.