Convective effects on columnar dendritic solidification – A multiscale dendritic needle network study

Gravity-induced buoyancy, inevitable in most solidification processes, substantially alters the dynamics of crystal growth, such that incorporating fluid flow models is crucial to understand and predict key aspects microstructure selection. Here, we present a multi-scale Dendritic Needle Network (DNN) model for directional includes buoyant liquid, apply it range alloys growth conditions. After brief presentation model, study selection stable primary dendrite arm spacings Al-4at.%Cu Ti-45at.%Al under different gravity levels, comparing both applications published phase-field results experimental measurements. Then, simulate oscillatory behavior recently reported via X-ray situ imaging nickel-based superalloy CMSX-4. In this last application, DNN simulations manage reproduce behavior, hence permit identifying fundamental mechanisms behind regime. particular, show sustained oscillations occur when average liquid velocity close velocity, dendritic also play role behavior.