Effects of Cu Distribution on Solidification Microstructure in Transition Layer of Cu/Al Composite Ingot Prepared by Casting Aluminum Method

In this study, a Cu/Al composite ingot was prepared by casting aluminum method, and the effects of the Cu concentration distribution in the transition layer on the solidification microstructure were examined during the recombination process of solid Cu and liquid Al. The results show that the Cu content is about 60% at the Cu/Al binding interface in the transition layer, while the Cu concentration first drops sharply and then decreases slowly in the direction away from the pure Cu. The concentration gradient of Cu reaches 1%/ mu m close to the Cu/Al binding surface. The Cu distribution in the transition layer does not change the microstructure species, but changes the proportions of various microstructures. The smaller the Cu concentration gradient is, the less the proportion of the hypoeutectic microstructure in transition layer is.