Effects of process parameters on the microstructure of Inconel 718 during powder bed fusion based on cellular automata approach

Abstract

Using numerical simulation methods in additive manufacturing (AM) processes can effectively reduce the cost of process exploration. This study presents a multi-scale simulation study based on the powder bed model for grain growth in the laser powder bed fusion (L-PBF) process of the Inconel 718 material. The finite volume method (FVM) and cellular automaton (CA) model were used to reproduce the process. The simulation results were consistent with the experimental results in terms of melt pool morphology, grain structure, and average grain size. The processes of the competitive and epitaxial growth of grains were discussed. The effects of laser power, scanning speed, hatch distance, and scanning strategy on microstructure were further analyzed through pole figure, grain area distribution, CA nucleation and capture event. The results demonstrated the feasibility of this method in predicting the evolution of microstructures in the L-PBF process and provide a reference for future research.

Keywords

• laser powder bed fusion
• inconel 718
• cellular automata
• finite volume method
• grain structure