Rapid growth of primary dendrite in highly undercooled copper-antimany alloy

【摘要】 <正> The droplets of Cu-11wt. %Sb hypoeutectic alloy have been rapidly solidified during containerless processing in a 3 m drop tube. The undercooling and cooling rates are estimated, and both play a dominant role in the dendritic growth of primary Cu phase. Undercoolings up to 200 K (0. I&TL, where TL is the liquidus temperature) have been obtained in the experiment. With the increase of undercooling, the microstructural evolution of primary Cu phase proceeds from remelted dendrites to the equiaxed grains. A coarse dendritic grain microstructure can form in the undercooling range of 61 - 102K and at cooling rates of 1.35X 102-2.66X 103K/s. The seg-regationless solidification of Cu-llwt. %Sb hypoeutectic alloy occurs when undercooling is more than 176 K. The growth of primary Cu phase is mainly controlled by solute diffusion.更多还原

【Abstract】 The droplets of Cu-11wt. %Sb hypoeutectic alloy have been rapidly solidified during containerless processing in a 3 m drop tube. The undercooling and cooling rates are estimated, and both play a dominant role in the dendritic growth of primary Cu phase. Undercoolings up to 200 K (0. I&TL, where TL is the liquidus temperature) have been obtained in the experiment. With the increase of undercooling, the microstructural evolution of primary Cu phase proceeds from remelted dendrites to the equiaxed grains. A coarse dendritic grain microstructure can form in the undercooling range of 61 - 102K and at cooling rates of 1.35X 102-2.66X 103K/s. The seg-regationless solidification of Cu-llwt. %Sb hypoeutectic alloy occurs when undercooling is more than 176 K. The growth of primary Cu phase is mainly controlled by solute diffusion.更多还原