Simulation of metal additive manufacturing microstructures using kinetic Monte Carlo

• Published in: Computational materials science Vol. 135; no. C; pp. 78 - 89
• Main Authors: Rodgers, Theron M., Madison, Jonathan D., Tikare, Veena
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2017; Elsevier
• Subjects: Additive manufacturing; Kinetic Monte Carlo; MATERIALS SCIENCE; MATHEMATICS AND COMPUTING; Microstructure; Microstructure; Kinetic Monte Carlo; Additive manufacturing
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2017.03.053

[Display omitted] •Novel Potts Monte Carlo-based model allows for the simulation of metal AM microstructures.•The method can simulate dozens of deposition layers and hundreds of passes.•Simulation results are compared against three distinct experimental results.•The model is freely available in the open-source SPPARKS Monte Carlo suite. Additive manufacturing (AM) is of tremendous interest given its ability to realize complex, non-traditional geometries in engineered structural materials. However, microstructures generated from AM processes can be equally, if not more, complex than their conventionally processed counterparts. While some microstructural features observed in AM may also occur in more traditional solidification processes, the introduction of spatially and temporally mobile heat sources can result in significant microstructural heterogeneity. While grain size and shape in metal AM structures are understood to be highly dependent on both local and global temperature profiles, the exact form of this relation is not well understood. Here, an idealized molten zone and temperature-dependent grain boundary mobility are implemented in a kinetic Monte Carlo model to predict three-dimensional grain structure in additively manufactured metals. To demonstrate the flexibility of the model, synthetic microstructures are generated under conditions mimicking relatively diverse experimental results present in the literature. Simulated microstructures are then qualitatively and quantitatively compared to their experimental complements and are shown to be in good agreement.