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 lambda is carried out for the tilted growth of dendritic arrays with different values of anisotropic to choose proper lambda 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 epsilon(4) for a wide range of misorientation angle Theta(0) in order to extend the DGP law. Results confirm that the coefficient f can be expressed as f(Theta(0), epsilon(4)) alpha(epsilon(4))chi(Theta(0)), where alpha(epsilon(4)) is an increasing function of epsilon(4) and chi(Theta(0)) solely depends on Theta(0) with a constant coefficient beta. Meanwhile, g(epsilon(4)) is a decreasing function of epsilon(4), 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. (C) 2016 Elsevier Ltd. All rights reserved.