Solidification of Al-xCu alloy under high pressures

In this study, Al-xCu alloy containing x = 15, 33, and 40 wt.% Cu was solidified under different pressures (atmospheric pressure, 1 GPa, 2 GPa, and 3 GPa). The effects of the solidification pressure and aging treatment on the microstructural evolution and mechanical property of these alloys were investigated. The eutectic Al2Cu phase varied between dendritic to spher- ical morphology in Al-15Cu alloy with the application of pressure. Both the secondary arm spacing in Al-33Cu alloy and the size of primary Al2Cu in Al-40Cu alloy had decreased under the influence of high pressure during solidification. As a result of solid solution strength- ening, the Vickers hardness increases significantly for the Al-xCu alloys with high-pressure solidification. The microstructure variation was further explained based on undercooling theory. (C) 2020 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).