LAUSR

Abstract Powder bed fusion is a recently developed additive manufacturing (AM) technique for alloys, which builds parts by selectively melting metallic powders with a high-energy laser or electron beam. Nevertheless, there is still a lack of fundamental understanding of the rapid solidification process for better quality control. To simulate the microstructure evolution of alloys during the rapid solidification, in this research, a mesoscale multi-physics model is developed to simultaneously consider solute transport, phase transition, heat transfer, latent heat, and melt flow. In this model, the phase-field method simulates the dendrite growth of alloys, whereas the thermal lattice Boltzmann method models heat transfer and fluid flow. The phase-field method and the thermal lattice Boltzmann method are tightly coupled. The simulation results of Ti-6Al-4V show that the consideration of latent heat is necessary because it reveals the details of the formation of secondary arms and provides more realistic kinetics of dendrite growth. The proposed multi-physics simulation model provides new insights into the complex solidification process in AM.