Numerical simulation using a coupled lattice Boltzmann–cellular automata method to predict the microstructure of Ti-6Al-4V after electron beam cold hearth melting

Abstract

A coupled lattice Boltzmann–cellular automata simulation method was developed to investigate the effects of electron beam heat sources on melt pool dynamics and process parameters on the microstructure of Ti-6Al-4V alloy during electron beam cold hearth melting (EBCHM) process. Temperature distribution and fluid flow behaviours within the melt pool were analysed, with findings indicating that an optimized beam power distribution leads to a more uniform temperature and stable melt pool profile, mitigating the risks of excessive melt vaporization. The simulation results reveal the influence of casting speed on melt pool depth, temperature gradients, and the columnar-to-equiaxed transition. The results indicate that higher casting speeds promote shallower melt pools and reduce temperature gradients, enhancing equiaxed grain nucleation and promoting more isotropic microstructures. This approach supports the effective control of microstructure and composition uniformity in EBCHM-produced ingots.