Coupling computational thermodynamics with density-function-theory based calculations to design L12 precipitates in Fe[sbnd]Ni based alloys

Ying Yang; German D. Samolyuk; Tianyi Chen; Jonathan D. Poplawsky; Andrew R. Lupini; Lizhen Tan; Littrell Ken

doi:10.1016/j.matdes.2020.108592

Coupling computational thermodynamics with density-function-theory based calculations to design L1₂ precipitates in Fe[sbnd]Ni based alloys

Ying Yang, German D. Samolyuk, Tianyi Chen, Jonathan D. Poplawsky, Andrew R. Lupini, Lizhen Tan, Littrell Ken

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Achieving a high-volume fraction of thermodynamically stable L1₂-type precipitates that are resistant to coarsening is of great importance for the development of low-cost Fe[sbnd]Ni based austenitic steels. With the aid of computational thermodynamics, this work designed two model alloys: Fe-37.4Ni-6.1Al-2.9Ti (FNAT) and Fe-45.2Ni-5.9Al-8.5Si (FNAS). Both alloys were designed to contain a similar amount of L1₂ precipitate in Fe-Ni matrix without forming other precipitates. Density-Function-Theory (DFT) calculation was coupled with computational thermodynamics to predict the critical radius at which the precipitates change shape from spherical to cuboidal. The calculation results suggest that critical radius for the FNAT alloy is about two orders of magnitude larger than that for the Fe[sbnd]Ni[sbnd]Al[sbnd]Si alloy. Phase stability and morphology of the L1₂ precipitates in these two alloys were experimentally investigated through X-ray diffraction, atom probe tomography, and scanning and transmission electron microscopy. The L1₂ precipitates in the Fe[sbnd]Ni[sbnd]Al[sbnd]Si system were found to be cuboidal and rod shaped, with much larger size than the spherical ones in the Fe[sbnd]Ni[sbnd]Al[sbnd]Ti system, agreeing with the calculation results. This work suggested that coupling computational thermodynamics with DFT calculations can be reliably used to design L1₂ precipitates in Fe[sbnd]Ni based alloys.

Original language	English
Article number	108592
Journal	Materials and Design
Volume	191
DOIs	https://doi.org/10.1016/j.matdes.2020.108592
State	Published - Jun 2020

Funding

This research was supported by the United States Department of Energy, Office of Science , Basic Energy Sciences , Materials Sciences and Engineering Division (data analysis and writing of the manuscript) and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL) (microstructural characterization and first-principles calculation), managed by UnT-Battelle, LLC, for the United States Department of Energy. YY acknowledges CompuTherm for providing the phase diagram calculation software Pandat. APT and STEM were conducted at ORNL’s Center for Nanophase Materials Sciences, which is a United States Department of Energy Office of Science User Facility. A portion of this research used resources at the High Flux Isotope Reactor, a Department of Energy Office of Science User Facility operated by the Oak Ridge National Laboratory . GDS would like to thank L. Vitos and W. Li for fruitful discussions. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a United States Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. This research was supported by the United States Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (data analysis and writing of the manuscript) and by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory (ORNL) (microstructural characterization and first-principles calculation), managed by UnT-Battelle, LLC, for the United States Department of Energy. YY acknowledges CompuTherm for providing the phase diagram calculation software Pandat. APT and STEM were conducted at ORNL's Center for Nanophase Materials Sciences, which is a United States Department of Energy Office of Science User Facility. A portion of this research used resources at the High Flux Isotope Reactor, a Department of Energy Office of Science User Facility operated by the Oak Ridge National Laboratory. GDS would like to thank L. Vitos and W. Li for fruitful discussions. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a United States Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. The raw/processed data required to reproduce these findings can be shared upon request.

Funders	Funder number
United States Department of Energy
United States Department of Energy Office of Science
U.S. Department of Energy	DE-AC02-05CH11231
Office of Science
Basic Energy Sciences
Oak Ridge National Laboratory
Division of Materials Sciences and Engineering

Keywords

CALPHAD
Density function theory
Fe[sbnd]Ni based alloys
Morphology
Precipitates

Access to Document

10.1016/j.matdes.2020.108592

Cite this

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title = "Coupling computational thermodynamics with density-function-theory based calculations to design L12 precipitates in Fe[sbnd]Ni based alloys",

abstract = "Achieving a high-volume fraction of thermodynamically stable L12-type precipitates that are resistant to coarsening is of great importance for the development of low-cost Fe[sbnd]Ni based austenitic steels. With the aid of computational thermodynamics, this work designed two model alloys: Fe-37.4Ni-6.1Al-2.9Ti (FNAT) and Fe-45.2Ni-5.9Al-8.5Si (FNAS). Both alloys were designed to contain a similar amount of L12 precipitate in Fe-Ni matrix without forming other precipitates. Density-Function-Theory (DFT) calculation was coupled with computational thermodynamics to predict the critical radius at which the precipitates change shape from spherical to cuboidal. The calculation results suggest that critical radius for the FNAT alloy is about two orders of magnitude larger than that for the Fe[sbnd]Ni[sbnd]Al[sbnd]Si alloy. Phase stability and morphology of the L12 precipitates in these two alloys were experimentally investigated through X-ray diffraction, atom probe tomography, and scanning and transmission electron microscopy. The L12 precipitates in the Fe[sbnd]Ni[sbnd]Al[sbnd]Si system were found to be cuboidal and rod shaped, with much larger size than the spherical ones in the Fe[sbnd]Ni[sbnd]Al[sbnd]Ti system, agreeing with the calculation results. This work suggested that coupling computational thermodynamics with DFT calculations can be reliably used to design L12 precipitates in Fe[sbnd]Ni based alloys.",

keywords = "CALPHAD, Density function theory, Fe[sbnd]Ni based alloys, Morphology, Precipitates",

author = "Ying Yang and Samolyuk, {German D.} and Tianyi Chen and Poplawsky, {Jonathan D.} and Lupini, {Andrew R.} and Lizhen Tan and Littrell Ken",

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year = "2020",

month = jun,

doi = "10.1016/j.matdes.2020.108592",

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AU - Samolyuk, German D.

AU - Chen, Tianyi

AU - Poplawsky, Jonathan D.

AU - Lupini, Andrew R.

AU - Tan, Lizhen

AU - Ken, Littrell

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AB - Achieving a high-volume fraction of thermodynamically stable L12-type precipitates that are resistant to coarsening is of great importance for the development of low-cost Fe[sbnd]Ni based austenitic steels. With the aid of computational thermodynamics, this work designed two model alloys: Fe-37.4Ni-6.1Al-2.9Ti (FNAT) and Fe-45.2Ni-5.9Al-8.5Si (FNAS). Both alloys were designed to contain a similar amount of L12 precipitate in Fe-Ni matrix without forming other precipitates. Density-Function-Theory (DFT) calculation was coupled with computational thermodynamics to predict the critical radius at which the precipitates change shape from spherical to cuboidal. The calculation results suggest that critical radius for the FNAT alloy is about two orders of magnitude larger than that for the Fe[sbnd]Ni[sbnd]Al[sbnd]Si alloy. Phase stability and morphology of the L12 precipitates in these two alloys were experimentally investigated through X-ray diffraction, atom probe tomography, and scanning and transmission electron microscopy. The L12 precipitates in the Fe[sbnd]Ni[sbnd]Al[sbnd]Si system were found to be cuboidal and rod shaped, with much larger size than the spherical ones in the Fe[sbnd]Ni[sbnd]Al[sbnd]Ti system, agreeing with the calculation results. This work suggested that coupling computational thermodynamics with DFT calculations can be reliably used to design L12 precipitates in Fe[sbnd]Ni based alloys.

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