On an expression for the growth of secondary dendrite arm spacing during non-equilibrium solidification of multicomponent alloys : validation against ternary aluminum-based alloys
ARTIGO
Inglês
Agradecimentos: The authors acknowledge the financial support provided by FAPERJ (The Scientific Research Foundation of the State of Rio de Janeiro, Brazil), FAPESP- São Paulo Research Foundation, Brazil (grant 2013/23396-7), CAPES and CNPq (The Brazilian Research Council)
The technological importance of the microstructure length scale is directly related to the influence exerted on solute redistribution and microporosity formation and on mechanical properties, such as, toughness, ductility, ultimate and yield tensile strengths. There is a huge lack of literature...
The technological importance of the microstructure length scale is directly related to the influence exerted on solute redistribution and microporosity formation and on mechanical properties, such as, toughness, ductility, ultimate and yield tensile strengths. There is a huge lack of literature concerning theoretical predictive dendritic growth models for unsteady-state solidification of multicomponent alloys. Most of the existing models have been proposed for steady-state solidification and for binary alloys. One of these models, initially restricted to binary alloys, has been extended for multicomponent alloys; however, it was shown to be valid only for low growth rates and small dendrite tip undercooling, that is, conditions that are very close to those of equilibrium cooling from the melt. In this paper, an extended approach is proposed, encompassing the back diffusion parameter to allow back diffusion treatment to be included in the analysis. A technique based on Butler’s formulation and on thermodynamic databases is used to permit necessary thermophysical parameters, such as the surface energy and the Gibbs-Thomson coefficient to be calculated for Al-Cu-(Si;Mg) alloys. Directional solidification apparatuses are used to provide a wide range of experimental solidification cooling rates and growth rates along the length of the directionally solidified castings. The model predictions are validated against the experimental scatters of secondary dendrite arm spacings of Al-Cu-Si; Mg) alloys castings solidified under transient upward and horizontal heat flow conditions. It is shown that the predictions fit quite well the experimental results
FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP
2013/23396-7
FUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJ
COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ
Fechado
On an expression for the growth of secondary dendrite arm spacing during non-equilibrium solidification of multicomponent alloys : validation against ternary aluminum-based alloys
On an expression for the growth of secondary dendrite arm spacing during non-equilibrium solidification of multicomponent alloys : validation against ternary aluminum-based alloys
Fontes
Journal of manufacturing processes Vol. Volume 35 (Oct., 2018), p. 634-650 |