Effect of concentration-gradient on characteristic parameters of α-Al dendrites in Al-Cu alloy

The alpha-Al dendrites of the Al-Cu alloy can maintain directional growth under concentration-gradient. Primary and secondary dendrite arm spacings, denoted lambda(1) and lambda(2), respectively, were measured to determine the Al-Cu concentration-gradient alloys that were solidified directionally at various concentration gradients (Gc), concentration (C) and cooling rates (RT). The lambda(1) and lambda(2) were expressed as functions of solidification parameters by using a regression analysis. The results were in good agreement with previous experimental work. This study provides some regression mathematical models to predict the microstructure of concentration-gradient alloys based on process parameters of the concentration-gradient, concentration and cooling rate, and it provides a path to design the properties of concentration-gradient alloys. (C) 2021 Elsevier B.V. All rights reserved.