Multi-scale simulation of microstructure evolution during direct laser deposition of Inconel718

As a free forming additive manufacturing technology for high performance metal parts, laser deposition manufacturing has a broad application prospect in aerospace and other fields. The solidification behavior and microstructure of molten pool determine the mechanical properties of the deposited parts. A multi-scale Cellular Automaton (CA)-Finite Element (FE) model is developed to simulate the microstructure evolution with different process parameters during the Direct Laser Deposition (DLD) process. Tempera -ture data and solidification parameters under different process parameters are obtained by finite element method, which establish connections between macroscopic temperature field and microstructure simula-tion. In addition, the effects of different process parameters on dendrite morphology, element segregation and grain structure are investigated. The primary dendrite arm spacing (PDAS), Nb element precipitation and grain size all increase with the increase of laser power, which are caused by the decrease of cooling rate. Moreover, the trend of the simulated results of microstructure under various process parameters are consistent with the experimental results.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Laser deposition manufacturing is a promising technology for high performance metal parts and has broad applications in aerospace and other fields. A multi-scale modeling approach is used to simulate the microstructure evolution during the process, and the effects of different process parameters are investigated. The simulated results are consistent with experimental observations.