Rapid dendritic growth and solute trapping within undercooled ternary Ni-5%Cu-5%Mo alloy

The dendritic growth velocity of α-Ni phase was measured as a function of undercooling in the nonequilibrium solidification process of an undercooled ternary Ni-5%Cu-5%Mo alloy. At the experimental maximum undercooling of 308 K (0.17T _L), the dendritic growth velocity attains 32 m/s. With the increase of undercooling, a morphological transition from dendrites into equiaxed grains occurs. Furthermore, the high dendritic growth velocity leads to the significant solute trapping of Cu and Mo elements and almost segregationless solidification is realized at the maximum undercooling.