Nature Materials News and Views on T. Haxhimali et al
James A. Warren
Simulations of dendritic solidification by T. Haxhimali et al.  for a pure material and comparisons with experiments in an A1Zn alloy system have shown that a standard theoretical rule of thumb for predicting solidification growth forms can dramatically fail. The researchers found that, in certain processing regimes, the solidification structures enter a hybrid hyperbranched state, where the growth forms are essentially a blend of two nearly energetically degenerate states. The loss of this rule-that the direction of growth coincides with the direction of minimum capillary pressure (the direction of minimum stiffness )-leaves the engineer with no simple analytic theory as a guide. Thus, desired growth forms may become unattainable in certain processing regimes, and time-consuming and expensive experimental and/or computational efforts will be required to address the complexities made apparent by this research. Indeed, this new work demonstrates that while great progress has been made over the past 50 years, our understanding of dendritic growth remains substantively deficient.
dendritic growth, orientation, solidification
Nature Materials News and Views on T. Haxhimali et al, Nature Materials
(Accessed June 9, 2023)