An Analysis of the Physical Properties of Multicomponent Alloy on the Simulation Solidification by Phase-Field Model

Abstract

A phase-field model is proposed for the simulation of microstructure and solute concentration during the solidification of Fe-C-P-Mn quaternary alloys. In this paper, a study is presented to analyze both the effects of partition coefficient and solute diffusivity on the microstructural evolution during solidification simulation. Partition coefficient and diffusivity are very important from a practical standpoint, because both parameters exert a strong influence on the dendrite morphology. Additionally, the proposed model is applied for quaternary alloys to the analysis of the time-dependent solidified fraction. Simulations permit to conclude that the solidified fraction is proportional to the square root of time, as expected for any diffusion-controlled growth process. Phase-field simulations on non-isothermal dendrite growth are also examined. Two-dimensional simulation results exhibit different dendrites in multicomponent alloys for different solute concentrations. Changes in the carbon concentration seem to affect the dendrite morphology, due to its higher concentration and its lower equilibrium partition coefficient. Changes in the phosphorus concentration affect the dendrite morphology and the interface velocity, when its content is increased from 10-3mol%P. Higher manganese content slows down the solidification kinetic, while the dendrite morphology remains unchanged.

Experimental Investigation of Ternary Al-Si-Cu Alloy Solidified with Unsteady-State Heat Flow Conditions

“…The solidification thermal parameters have influence on the microstructure and microsegregation andthese, in turn, are key featuresin inducing non-uniformity on the as-cast material mechanical properties. For this reason, the microstructure and microsegregation has been extensively studied both theoretically [1][2][3][4][5][6][7][8][9][10][11] and experimentally [12][13][14][15][16][17][18][19][20][21][22][23][24][25] for the last decades. The Al-1.2wt%Pb and Al-3.2wt%Bi alloys have been chosen by Freitas et al 13 , to study the effect of microstructural parameters on the wear process.…”

“…where C S is the concentration in the solid region, C 0 the initial overall composition and F S the solid fraction. Although the influence of solidification speed (V L ) and cooling rate ( ) on the microstructural characteristics was the focus of many studies [1][2][3][4][12][13][14][15][16] , literature on the influence of these parameters on the microsegregation profiles are still quite limited 21 . Burton et al 9 proposed an equation for effective distribution coefficient (K ef ) as a function of the solidification speed (V L ).…”

“…The equilibrium partition coefficient can be replaced by this effective distribution coefficient into the Scheil microsegregation model. Burton proposes the following equation for K ef (2) where δ diffusion layer thickness of the segregated solute ahead the solid/liquid interface and D L is the liquid solute diffusivity. Physical properties adopted for this work were the same those used by Qiang et al 5 and Wesner et al 6 and are shown in Table 1.…”

Phase-Field Simulation of Microsegregation and Dendritic Growth During Solidification of Hypoeutectic Al-Cu alloys

“…The solidification process of alloys has been studied by Salvino et al 1,2 It is shown, in said work, the phase-field model applied to the multicomponent alloy solidification (Fe-C-P-Mn) for equiaxed dendritic growth. The papers provide an introduction to the phase-field model and an overview of its possibilities.…”

“…The effect of cooling rate on the secondary dendrite arm spacing and microsegregation was investigated through comparison with the experimental results. The previous works [1][2][3][4][5][6] indicate that the phase-field model is a versatile and powerful technique for calculating the evolution of microstructure, which is very popular nowadays.…”