Agradecimentos: The authors acknowledge the financial support provided by Federal Institute of Education, Science and Technology of Para-IFPA, FAPESP (The Scientific Research Foundation of the State of São Paulo, Brazil), FAPERJ (The Scientific Research Foundation of the State of Rio de Janeiro),...

Agradecimentos: The authors acknowledge the financial support provided by Federal Institute of Education, Science and Technology of Para-IFPA, FAPESP (The Scientific Research Foundation of the State of São Paulo, Brazil), FAPERJ (The Scientific Research Foundation of the State of Rio de Janeiro), CAPES and CNPq (The Brazilian Research Council)

Experiments of vertical unsteady-state directional solidification were carried out in order to permit the influence of copper alloying to Al-Si alloys on the scale of secondary dendritic arm (λ2) to be investigated. The microstructures of Al-nSi-3wt%Cu alloys, with “n” equal to 5.5wt%Si and...

Experiments of vertical unsteady-state directional solidification were carried out in order to permit the influence of copper alloying to Al-Si alloys on the scale of secondary dendritic arm (λ2) to be investigated. The microstructures of Al-nSi-3wt%Cu alloys, with “n” equal to 5.5wt%Si and 9.0wt%Si, were characterized and correlated with solidification thermal parameters: the growth rate (VL), the tip cooling rate (ṪL) and the local solidification time (tSL). A comparative analysis between the present results and those from the literature related to the secondary dendrite growth during directional solidification of Al-nSi alloys is also conducted. It is shown that the addition of Cu to both Al-nSi alloys decreases λ2, and experimental growth laws relating λ2 to VL and ṪL are proposed for the ternary alloys examined. The experimental scatter of λ2 is also compared with the only theoretical dendritic growth model from the literature for multicomponent alloys, and it is shown that the theoretical predictions overestimate the present experimental results

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJ

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

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