Evaluation of the effect of artificial re-gassing of aluminium melts after ultrasonic treatment

Abstract

Ultrasonic treatment of aluminium melts is known as an efficient process to remove dissolved hydrogen. Whereas the degassing efficiency of ultrasonic treatment has been extensively reported, the effect of re-gassing after the ultrasonic treatment is much less studied. The present investigation attempts to evaluate the effect of artificial re-gassing of aluminium melts after ultrasonic treatment was applied. The results show an increase in porosity after artificial re-gassing after ultrasonic treatment compared to artificial gassing before the ultrasonic treatment was applied. An increase of potent nucleation sites for gas porosity after ultrasonic treatment by unfolding and/or break-up of bifilms is supposed.

UQ eSpace

“…However, it may play a role in the process of degassing [38]. It has also been found that the effect of solute metals has a more significant role in grain refinement than UST, although UST does further refine the grain structure [13,43,46,47].…”

“…UST degassing provides advantages over traditional methods as it does not require the extra cost of purging gases and only releases the dissolved hydrogen into the melt. There is extensive literature on UST degassing and it has been found that it can reduce dissolved hydrogen amounts by 40-50% [12,37,38].…”