Effect of ultrasound treatment on Cu-Zn alloys

The application of power ultrasound to liquid and solidifying alloys is known to allow the formation of a nondendriticand fine microstructure suitable for semi-solid feedstock production. In literature several papersreport results about low melting point alloys but very limited data are available on Cu-base alloys.The aim of this paper is, therefore, to evaluate the effect of ultrasonic waves applied to Cu alloys duringsolidification in order to obtain a globular microstructure.Metallographic analyses showed the effectiveness of this technique in breaking the forming dendrites, givingrise to an almost globular structure, suitable for being used in semi-solid processing.The differences in microstructure morphology and phases composition resulted to affect the corrosionresistance of the analysed samples, in particular the semi-solid ones showed improved performance as aconsequence of the homogenizing effect induced by the ultrasound treatment