Solidificação de ligas hipo-eutéticas Pb-Sb super-resfriadas pela técnica de fluxo.

Abstract

This work aimed at the study of the solidification of undercooled Pb-Sb alloys by the fluxing technique. Flux technique has been used to reduce nucleation sites and produce increased undercooling in metals and alloys. In this work, hypoeutectic alloys were solidified by fluxing technique. The samples undercooled by flux obtained undercooling level bigger than the samples undercooled without flux. The flux can have trapped impurities during solidification, increasing undercooling. The microstructures were investigated as a function of the undercooling level. For this alloys, a morphological change occurs with increasing undercooling and was accompanied by a refinement of the primary dendrites Pb phase and eutectic. The crystal growth velocity usually increases when undercooling increases, provoked changes morphology in primary phase and eutectic.