Effect of Ultrasounds during the Solidification Process of the A357 Aluminium Alloy

Abstract

It is known that ultrasonic waves promote nucleation and globulization of solid particles in aluminium alloys. However, the studies performed up to date have been conducted, in the laboratory, using small volumes of aluminium. This article aims to establish the application of ultrasound effect in the A357 aluminium-silicon alloy in amounts of about 2 kg of material. The experiments have been conducted with different parameters of ultrasonic treatment, evaluating the microstructure of the slurry quenched from the semi-solid state. The globulization effect of aluminium α phase by ultrasounds is very effective in the area close to the ultrasonic horn tip and the transmission system, but its effect highly reduces in the regions far away from the source of ultrasonic waves.

Rheological Behavior of the A356 Alloy in the Semisolid State at Low Shear Rates

“…The authors base this study on their extensive knowledge about the thixotropic forming of aluminum alloys [ 5 , 6 , 7 , 8 ] whose rheological behavior in the semisolid state will be key for its printing by FDM type technologies.…”