Ultrasonic vibration as a primary mixing tool in accelerating aluminum–copper alloys preparation from their pure elements

In this study, ultrasonic vibration (USV) was evaluated in preparation of Al–8wt.%Cu alloys at a lab-scale. Moreover, the role of Ti–6Al–4V sonotrode erosion and its contribution in grain refining were analyzed. Based on the experimental conditions/parameters, it was found that the amount of impurities and the associated porosity were significantly reduced in USV treated alloys. Furthermore, USV reduced the time needed for dissolving the alloying element Cu, nevertheless, the best dissolving of Cu in this study was not possible without introducing further holding time. As a result of using a titanium-based sonotrode, a noticeable content of Ti was found in the ultrasonically treated alloys due to sonotrode erosion under USV. The dispersion of TiAl3 promoted, as a main factor, a grain refining effect at relatively constant and high melt temperature, other possible mechanisms of grain refining have been discussed.This work is supported by Erasmus Mundus through PEACE II Lot 2 Project 2013-2443/001-001-EMA2 and FCT with the reference project UID/EEA/04436/2013, COMPETE 2020, with the code POCI-01-0145-FEDER-006941