Equiaxed dendritic growth in nearly isothermal conditions: A study combining in situ and real-time experiment with large-scale phase-field simulation

• Solidification experiments of Al-Cu alloys are observed in situ and real-time. Large-scale 2D PF simulations solidification realized. Effects cooling rate liquid flow on multi-grain growth discussed. The equiaxed dendritic nearly isothermal temperature field under continuous condition is studied using real-time observation by synchrotron X-ray radiography large-scale quantitative two-dimensional (2D) phase-field (PF) simulations. It revealed that the morphology secondary arm spacing (SDAS) a reasonable agreement with experimental data. Increasing rates results smaller SDAS, as predicted analytical Kattamis-Flemings model. transformation kinetics solid fraction can be described Johnson-Mehl-Avrami-Kologoromov (JMAK) theory, but differences between significant. maximum solute concentration C max approximately equal to equilibrium concentration, which depends undercooling rather than rate. But minimum min decreases rate, thus leading larger segregation ratio S R = / . Moreover, gravity-driven natural convection considered slightly increases SDAS has no apparent effect fraction, reduced convection, could attributed almost same enlarged