Directional Solidification of Undercooled Hypoeutectic Silver-Copper Alloy Melt
Directional solidification of the undercooled melt which combines melt undercooling with conventional directional solidification is a new method of obtaining directional structure. This method is used to realize the directional solidification of the undercooled Ag70.3Cu29.7 melt. The experiment is performed in two steps: The undercooled melt is obtained by glass fluxing, and the above specimen is remelted and excited with Ga-In-Sn coolant. By this method, directional solidification dendrites of Ag70.3Cu29.7 alloy are achieved successfully. The columnar dendrites are straight and fine. The primary arm spacing is 21µm in average for a 65K undercooling, as compared to 38µm for a 32K undercooling. This confirms that higher undercooling promotes finer dendritic microstructures.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
Y. Y. Lu et al., "Directional Solidification of Undercooled Hypoeutectic Silver-Copper Alloy Melt", Materials Science Forum, Vols. 475-479, pp. 2607-2610, 2005