Effect of interface anisotropy on growth direction of tilted dendritic arrays in directional solidification of alloys: Insights from phase-field simulations

We investigate the effect of interfacial anisotropy on the growth direction selection during directional solidification of alloys by using the thin-interface phase-field model. A convergence study with respect to the coupling constant λ is carried out for the tilted growth of dendritic arrays with different values of anisotropic to choose proper λ in simulations. The influence of the artificial noise at the interface on the growth direction selection is discussed. By analyzing the data from two-dimensional phase-field simulations, we discuss the dependence of the coefficients f and g in DGP law (Deschamps et al., 2008) on anisotropic strength ε4 for a wide range of misorientation angle Θ0 in order to extend the DGP law. Results confirm that the coefficient f can be expressed as f(Θ0,ε4)≡α(ε4)χ(Θ0), where α(ε4) is an increasing function of ε4 and χ(Θ0) solely depends on Θ0 with a constant coefficient β. Meanwhile, g(ε4) is a decreasing function of ε4, which can be modeled by a power-law function. Moreover, we comment on the influence of the pulling velocity on the growth direction selection for a wider range of the pulling velocity.