Comparison of Dynamical and Empirical Simulation Methods of Secondary Dendrite Arm Coarsening

The physical and mechanical properties of an entirely (wrought alloys) or partly (cast dendritically solidified alloy strongly depend on the secondary dendrite arm spacing (SDAS). casting practice simulation solidification need a usable but simple method to calculate SDAS during at end as function cooling rate. Based many experiments, equation (empirical method) is known use local time, which can be obtained from measured curves (equiaxed solidification), calculated temperature gradient front velocity (directional solidification). This not for calculating solidification. Kirkwood developed semi-empirical based liquid phase’s diffusion, contains only one geometric factor that seems constant different alloys. some parameters temperature, so cannot integral in closed form. In present work, first, we show effect curvature solid/liquid interface equilibrium concentrations then processes SDA coarsening. our earlier paper, demonstrated using empirical method, final with acceptable correctness case four unidirectional experiments Al-7wt%Si alloy. work shows numerically integrated Kirkwood’s equations used curve; good agreement these experimental results. Compared two calculation methods, stated methods similar. Still, results (the microsegregation) will more correct dynamical method. It also shown any type curve, it proved SDASs could belong same time.