Artículos de revistas
Gravity-driven inverse segregation during transient upward directional solidification of Sn-Pb hypoeutectic alloys
Registro en:
Journal Of Alloys And Compounds. Elsevier Science Sa, v. 475, n. 41671, n. 396, n. 400, 2009.
0925-8388
WOS:000265911700087
10.1016/j.jallcom.2008.07.024
Autor
Ferreira, IL
Spinelli, JE
Garcia, A
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Upward unidirectional solidification experiments were performed with Sn-4.0wt.%Pb and Sn-12.5wt.%Pb alloys. Transitory conditions of heat flow extraction were sustained during these solidification experiments, which mean that all solidification variables (cooling rate, tip growth rate, thermal gradient, and metal/mold heat transfer coefficient) have varied freely along solidification. In this work, the macrosegregation phenomenon is experimentally and theoretically evaluated considering both solidification shrinkage and gravity induced flows. The numerical model is based on a one-dimensional solution consisting of an implicit/explicit time integration scheme to couple thermal and solutal fields, which is supported by a finite volume numerical modeling technique to be solved. The applied solidification system permitted columnar growth to prevail along the castings. Since the Pb-rich melt tends to flow downward (in favor of the gravity vector), the bottom of the castings exhibited positive Pb content, mainly induced by gravity. The numerically simulated and experimental temperature and concentration profiles were compared and a very good agreement has been observed. (C) 2008 Elsevier B.V. All rights reserved. 475 41671 396 400 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) FAEPEX-UNICAMP Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)