A Coupled DEM/SPH Computational Model to Simulate Microstructure Evolution in Ti-6Al-4V Laser Powder Bed Fusion Processes

A new multi-stage three-dimensional transient computational model to simulate powder bed fusion (L-PBF) additive manufacturing (AM) processes is presented. The uses the discrete element method (DEM) for flow simulation, an extended smoothed particle hydrodynamics (SPH) melt pool dynamics and a semi-empirical microstructure evolution strategy evolving temperature of non-spherical Ti-6Al-4V grains undergoing L-PBF. highly novel use both DEM SPH means that varied physics such as collisions between during coating process heat transfer, melting, solidification laser can be simulated. capability demonstrated by applying complex representative scan pattern single-layer bed. It found fast cooling rate primarily leads transition ? ? martensitic phases. minimal production Widmanstatten phase at outer edge also noted due in situ treatment effect near laser. This work demonstrates potential coupled DEM/SPH realistic tool investigate parameters morphology, speed power characteristics on microstructure.