Solidificação de ligas Al-Si super resfriadas pela técnica de fluxo.

Abstract

This work aimed at the study of the solidification Al-Si alloys by the fluxing technique.The results showed that technique was efficient to obtain large undercoolings. The increasing undercooling was observed when the alloys used B2O3 as flux. The flux B2O3, probably, acted in removed impurities or changed structures and make them less active, and/or isolated the molten metal from contact with the crucible and atmosphere.I lowevcr, a morphological change did not occur in spit of increasing of undercooling. That is probable of the critical undercooling unattainable in the alloys.The results showed that the increasing of the solute for hypoeuteclic alloys decreased the level undercooling, probably of the solute Si has growth faceted.