Solidification and grain formation in alloys: a 2D application of the grand-potential-based phase-field approach

Journal Article · 10 January 2022 · Modelling and Simulation in Materials Science and Engineering

DOI: https://doi.org/10.1088/1361-651x/ac46dc · OSTI ID:1987460

Biswas, Sudipta  ^[1]; Liu, Dehao  ^[2]; Aagesen, Jr., Larry K.  ^[1]; Jiang, Wen ^[1]

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1. Idaho National Laboratory (INL), Idaho Falls, ID (United States)
2. Georgia Institute of Technology, Atlanta, GA (United States)

Solidification is a significant step in the forming of crystalline structures during various manufacturing and material processing techniques. Solidification characteristics and the microstructures formed during the process dictate the properties and performance of the materials. Hence, understanding how the process conditions relate to various microstructure formations is paramount. In this work, a grand-potential-based multi-phase, multi-component, multi-order-parameter phase-field model is used to demonstrate the solidification of alloys in 2D. This model has several key advantages over other multi-phase models such as it decouples the bulk energy from the interfacial energy, removes the constraints for the phase concentration variable, and prevents spurious third-phase formation at the two phase interfaces. Here, the model is implemented in a finite-element-based phase-field modeling code. The role of various modeling parameters in governing the solidification rate and the shape of the solidified structure is evaluated. It is demonstrated that the process conditions such as temperature gradient, thermal diffusion, cooling rate, etc, influence the solidification characteristics by altering the level of undercooling. Furthermore, the capability of the model to capture directional solidification and polycrystalline structure formation exhibiting various grain shapes is illustrated. In both these cases, the process conditions have been related to the growth rate and associated shape of the dendritic structure. As a result, this work serves as a stepping stone towards resolving the larger problem of understanding the process–structure–property–performance correlation in solidified materials.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 1987460
• Report Number(s): INL/JOU-21-62598-Rev000
• Journal Information: Modelling and Simulation in Materials Science and Engineering, Journal Name: Modelling and Simulation in Materials Science and Engineering Journal Issue: 2 Vol. 30; ISSN 0965-0393
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English