Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting

Sames, William J.; Unocic, Kinga A.; Dehoff, Ryan R.; Lolla, Tapasvi; Babu, Sudarsanam Suresh

doi:10.1557/jmr.2014.140

Title: Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting

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Abstract

Additive manufacturing (AM) technologies, also known as 3D printing, have demonstrated the potential to fabricate complex geometrical components, but the resulting microstructures and mechanical properties of these materials are not well understood due to unique and complex thermal cycles observed during processing. The electron beam melting (EBM) process is unique because the powder bed temperature can be elevated and maintained at temperatures over 1000 °C for the duration of the process. This results in three specific stages of microstructural phase evolution: (a) rapid cool down from the melting temperature to the process temperature, (b) extended hold at the process temperature, and (c) slow cool down to the room temperature. In this work, the mechanisms for reported microstructural differences in EBM are rationalized for Inconel 718 based on measured thermal cycles, preliminary thermal modeling, and computational thermodynamics models. The relationship between processing parameters, solidification microstructure, interdendritic segregation, and phase precipitation (δ, γ´, and γ´´) are discussed.

Authors:

Sames, William J. ^[1]; Unocic, Kinga A. ^[2]; Dehoff, Ryan R. ^[2]; Lolla, Tapasvi ^[3]; Babu, Sudarsanam Suresh ^[4]

Texas A & M Univ., College Station, TX (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
The Ohio State Univ., Columbus, OH (United States)
Univ. of Tennessee, Knoxville, TN (United States)

Publication Date:: Mon Jul 28 00:00:00 EDT 2014

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:: 1224156

DOE Contract Number:: AC05-00OR22725

Resource Type:: Journal Article

Journal Name:: Journal of Materials Research

Additional Journal Information:: Journal Volume: 29; Journal Issue: 17; Journal ID: ISSN 0884-2914

Publisher:: Materials Research Society

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE

Citation Formats


                    Sames, William J., Unocic, Kinga A., Dehoff, Ryan R., Lolla, Tapasvi, and Babu, Sudarsanam Suresh. Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting.  United States: N. p., 2014. 
        Web.  doi:10.1557/jmr.2014.140.

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                    Sames, William J., Unocic, Kinga A., Dehoff, Ryan R., Lolla, Tapasvi, & Babu, Sudarsanam Suresh. Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting.  United States.  https://doi.org/10.1557/jmr.2014.140

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                    Sames, William J., Unocic, Kinga A., Dehoff, Ryan R., Lolla, Tapasvi, and Babu, Sudarsanam Suresh. 2014.  
        "Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting".  United States.  https://doi.org/10.1557/jmr.2014.140.

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@article{osti_1224156,

  title        = {Thermal Effects on Microstructural Heterogeneity of Inconel 718 Materials Fabricated by Electron Beam Melting},

  author       = {Sames, William J. and Unocic, Kinga A. and Dehoff, Ryan R. and Lolla, Tapasvi and Babu, Sudarsanam Suresh},

  abstractNote = {Additive manufacturing (AM) technologies, also known as 3D printing, have demonstrated the potential to fabricate complex geometrical components, but the resulting microstructures and mechanical properties of these materials are not well understood due to unique and complex thermal cycles observed during processing. The electron beam melting (EBM) process is unique because the powder bed temperature can be elevated and maintained at temperatures over 1000 °C for the duration of the process. This results in three specific stages of microstructural phase evolution: (a) rapid cool down from the melting temperature to the process temperature, (b) extended hold at the process temperature, and (c) slow cool down to the room temperature. In this work, the mechanisms for reported microstructural differences in EBM are rationalized for Inconel 718 based on measured thermal cycles, preliminary thermal modeling, and computational thermodynamics models. The relationship between processing parameters, solidification microstructure, interdendritic segregation, and phase precipitation (δ, γ´, and γ´´) are discussed.},

  doi          = {10.1557/jmr.2014.140},

  url          = {https://www.osti.gov/biblio/1224156},
  journal      = {Journal of Materials Research},

  issn         = {0884-2914},

  number       = 17,

  volume       = 29,

  place        = {United States},

  year         = {Mon Jul 28 00:00:00 EDT 2014},

  month        = {Mon Jul 28 00:00:00 EDT 2014}

}

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