Quantitative phase-field simulations of globulitic solidification from the critical nucleus with the effects of interface curvature and attachment kinetics

Autor(es)

Maciel, R. R. ^[1] ; Martorano, M. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Met & Mat Engn, Av Prof Mello Moraes 2463, BR-05508900 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: COMPUTATIONAL MATERIALS SCIENCE; v. 198, OCT 2021.
• Citações Web of Science: 0

Resumo

A one-dimensional quantitative phase-field model (thin-interface approximation) considering the effects of interface curvature and attachment kinetics was implemented to simulate the solidification of a solid sphere (globulitic solidification) of a pure substance in an undercooled infinite melt, beginning from the critical nucleus. The classical sharp interface model for the same problem was also solved and the growth velocity and interface temperature were calculated and compared with the results of the phase-field model. Numerical conditions of the phase-field model, namely interface thickness, numerical mesh spacing, and critical nucleus model, that give close agreement with the sharp interface model (quantitative modeling) were determined. The possibility of a unique controlling step of the overall solidification kinetics by heat transfer or interface attachment kinetics or even of a mixed control was analyzed by defining relative undercoolings at the solid-liquid interface. For both metallic and non-metallic materials, growth is initially controlled by interface attachment kinetics, but, as the solid sphere grows and the melt heats up, it changes to the mixed control regime with heat transfer before spherical growth becomes unstable. The spherical radius for the change to mixed control increases when the kinetic coefficient or the magnitude of melt undercooling increases, because the heat transfer step is facilitated relative to that of attachment kinetics. (AU)

• Processo FAPESP: 17/22361-6 - Efeito da convecção do líquido na purificação do silício por solidificação direcional para aplicações fotovoltaicas
• Beneficiário: Marcelo de Aquino Martorano
• Modalidade de apoio: Auxílio à Pesquisa - Regular