抄録
The isothermal dendritic growth process of an Al–Cu binary alloy was simulated by utilizing the phase-field method. The morphology forming process of the α phase of the aluminum rich Al–Cu system was clarified dynamically. Lower the growth temperature, faster the growth velocity of the dendrite primary arm and finer the dendrite structure. In addition, it was confirmed that the degree of segregation of Cu in dendrite arms became evident in increasing supercooling. The growth velocity of primary dendrite arm V can be expressed as a function of dimensionless supercooling Δ and Cu atomic concentration c such that V [× 105 μm/s] = (1160–124c)Δ2.45. The radius of the dendrite primary arm d does not depend on Cu atomic concentration c but on dimensionless supercooling Δ as d[μm]=0.0818Δ−0.543. Dimensionless supersaturation Δc is a function of Peclet number P= (Vd/2DL) such that Δc = 0.929 + 1.2002 (1⁄P)2 -1.4128 (1⁄P).
