Application of ultrasonic treating to degassing of metal ingots

The relations between porosity in the ingot and the effecting factors such as the ultrasonic power and the time of ultrasonic vibration (UV) treating to melt were investigated. Moreover, the mechanism of the porosity formation and the prevention method was studied. The results indicate that the effect of degasification was better when the intensity of UV is above threshold value. On the contrary, the intensity of UV below the value resulted in the increase of the gas content in the ingot and the decrease of density. It could be confirmed that there is an appropriate time on degasification by UV treating. When treating time is over the time. the density of the ingot tended to decrease. By using UV to degas with constraint cooling in the bottom of the ingot, the value of porosity volume (PV) can be decreased below 0.1 cm(3)/100 g and the eta(deg) is near to 97%. (C) 2008 Elsevier B.V. All rights reserved.