Metallurgical and Materials Transactions A

, Volume 49, Issue 11, pp 5775–5798 | Cite as

Process-Defect-Structure-Property Correlations During Laser Powder Bed Fusion of Alloy 718: Role of In Situ and Ex Situ Characterizations

  • S. J. Foster
  • K. Carver
  • R. B. Dinwiddie
  • F. ListIII
  • K. A. Unocic
  • A. Chaudhary
  • S. S. BabuEmail author


Components made by laser powder bed fusion (L-PBF) additive processes require extensive trial and error optimization to minimize defects and arrive at targeted microstructure and properties. In this work, in situ infrared thermography and ex situ surface roughness measurements were explored as methodologies to ensure Inconel® 718-part quality. For a given laser energy of 200 Watts, prismatic samples were produced with different exposure times (80 to 110 µs) and point spacings (80 to 110 µm). The infrared intensities from laser–material interaction zones were measured spatially and temporally. The conditions leading to higher IR intensity and lowest surface roughness values correlated well with less porosity and coarse solidification grain structure. The transition from highly columnar to misoriented growth is attributed to changes in thermal gradients and liquid–solid interface velocities. Hardness measurements and electron microscopy of the as-processed and post-processed heat-treated samples show complex transitions in microstructural states including the heavily dislocated FCC matrix, reduction of dislocation density, and copious precipitation, respectively. These results show that the geometry-process-structure-property correlations are dynamic, and they cascade depending on the transitions of phase states from powder to liquid to solid, as well as phase decompositions and deformations within the solid FCC phase. Validity of using analytical weld process models to describe the above phenomena is also highlighted.



The authors of this work would like to acknowledge and thank the funding contributor Applied Optimization, Inc. under the NASA STTR Phase II program (Contract Number: NNX15CA24C). Part of the research is based upon work supported by the US Department of Energy, Office of Energy, Efficiency, and Renewable Energy, Advanced Manufacturing Office under Contract Number DE-AC05-00OR22725. The microscopy was supported by using instrumentation (FEI Talos F200X S/TEM) provided by the Department of Energy, Office of Nuclear Energy, Fuel Cycle R&D Program and the Nuclear Science User Facilities. D.W. Coffey assisted with the experimental work. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan. (


  1. 1.
    R. A. Roach and S. H. Gardner, Translational Materials Research, 2017, Vol. 4, 044001CrossRefGoogle Scholar
  2. 2.
    M. Seifi, M. Gorelik, J. Waller, N. Hrabe, N. Shamsaei, S. Daniewicz, and J. J. Lewandowski, JOM, 2017, Vol. 69, pp. 439-455CrossRefGoogle Scholar
  3. 3.
    B. H. Jared, M. A. Aguilo, L. L. Behini, B. L. Boyce, B. W. Clark, A. Cook, B. J. Kaehr, and J. Robbins, Scripta Materialia, 2017, Vol. 135, pp. 141-147CrossRefGoogle Scholar
  4. 4.
    NIST: Measurement Science Roadmap for Metal-based Additive Manufacturing, prepared by Energetics Incorporated, 2013.
  5. 5.
    S.K. Everton, M. Hirsch, P.Stravroulakis, R.K. Leach, and A.T. Clare, Mater. Des. 2016, Vol. 95, pp. 431–445CrossRefGoogle Scholar
  6. 6.
    H. Krauss, C. Eschey, and M.F. Zaeh: Proc. 23rd Annu. Int. Solid Free. Fabr. Symp. 2012, pp. 999–1014,
  7. 7.
    S. Clijsters, T. Craeghs, S. Buls, K. Kempen, and J. P. Kruth., Int. J. Adv. Manuf. Technol. 2014, Vol. 75, pp. 1089–1101CrossRefGoogle Scholar
  8. 8.
    R.B. Dinwiddie, R.R. Dehoff, P.D. Lloyd, L.E. Lowe, and J.B. Ulrich, Thermo-sense Therm. Infrared Appl. Xxxv, 2013, Vol. 8705, pp. 1–9Google Scholar
  9. 9.
    R.B. Dinwiddie, M.M. Kirka, P.D. Lyod, R.R. Dehoff, L.E. Lowe, G.S. Marlow: Proc. SPIE, 2016, Vol. 9861.
  10. 10.
    S. Moylan, E. Whitenton, B. Lane, and J. Slotwinski: 40th Annu. Rev. Prog. Quant. Nondestruct. Eval., AIP Conf. Proc. 2014, Vol. 1581, pp. 1191–96.
  11. 11.
    G. Marshall, W.J. Young II, N. Shamsaei, J. Craig, T. Wakeman, and S.M. Thompson: Proc. Solid State Free Form. 2015, pp. 259–72.
  12. 12.
    E. Rodriguez, J. Mireles, C. Terrazas, D. Espalin, M. Perez, and R.B. Wicker, Additive Manufacturing., 2015, Vol. 5, pp. 31–39, CrossRefGoogle Scholar
  13. 13.
    M. Doubenskaia, M. Pavlov, S. Grigoriev, and I. Smurov, Surf. Coatings Technol., 2013, Vol. 220, pp. 244–247, CrossRefGoogle Scholar
  14. 14.
    G. Bi, A. Gasser, K. Wissenbach, A. Drenker, and R. Poprawe, Opt. Lasers Eng., 2006, Vol. 44, pp. 1348–1359, CrossRefGoogle Scholar
  15. 15.
    P. Lott, H. Schleifenbaum, W. Meiners, K. Wissenbacj, C. Hinke and J. Bultmann, Physics Procedia, 2011, Vol. 12, pp. 683-690CrossRefGoogle Scholar
  16. 16.
    W. S. Land II, B. Zhang, J. Ziegert and A. Davies, Procedia Manufacturing, 2015, Vol. 1, pp. 393-403CrossRefGoogle Scholar
  17. 17.
    S. Huber, J. Glasschroeder and M. F. Zaeh, Physics Procedia, 2011, Vol. 12, pp. 712-719CrossRefGoogle Scholar
  18. 18.
    L. Mrna and M. Sarbort, Physics Procedia, 2014, Vol. 56, pp. 1261-1267CrossRefGoogle Scholar
  19. 19.
    M. Schwalbe: Predicting theoretical and computational approaches for additive manufacturing. Proc. Workshop Natl. Acad. Sci., 2016Google Scholar
  20. 20.
    ISO/ASTM 52900:2015(E): Standard terminology for additive manufacturing – General principles – Terminology, ASTM International, 2016Google Scholar
  21. 21.
    I. Yadroitsev, A. Gusarov, I. Yadroitdave, I. Smurov, J. Mater. Process. Technol., 2010, Vol. 210, pp. 1624-1631CrossRefGoogle Scholar
  22. 22.
    I. Yadroitsev and I. Smurov, Physics Procedia, 2010, Vol. 5, pp. 551-560CrossRefGoogle Scholar
  23. 23.
    S. Tammas-Williams, H. Zhao, F. Leonard, F. Derguti, I. Todd, and P.B. Prangnell, Materials Characterization, 2015, Vopl. 102, pp. 47-61CrossRefGoogle Scholar
  24. 24.
    W. Sames, F. A. List, S. Pannala, R. R. Dehoff and S. S. Babu, International Materials Reviews, 2016, Vol. 61, pp. 315-360CrossRefGoogle Scholar
  25. 25.
    S.S. Babu: in Introduction to Integrated Weld Modeling. ASM Handbook, D.U. Furrer and S.L. Semiatin, eds., ASM International, 2010, vol. 22B.Google Scholar
  26. 26.
    S. Yoder, S. Morgan, E. Barnes, C. Kinzy, P. Nandwana, M. Kirka, S. S. Babu, V. Paquit, and R. R. Dehoff, Additive Manufacturing, 2018, Vol. 19, pp. 184-196CrossRefGoogle Scholar
  27. 27.
    A. Plotkowski, M. M. Kirka, and S. S. Babu, Additive Manufacturing, 2017, Vol. 18, pp. 256-268CrossRefGoogle Scholar
  28. 28.
    N. Raghavan, A. Plotkowski, R. R. Dehoff, J. A. Turner, M. K. Kirka, and S. S. Babu, Acta Materialia, 2017, Vol. 140, pp. 375-387CrossRefGoogle Scholar
  29. 29.
    Z. C. Cordero, R. B. Dinwiddie, and R. R. Dehoff, Journal of Materials Science, 2017, Vol. 52, pp. 3429-3435CrossRefGoogle Scholar
  30. 30.
    N. Raghavan, S. S. Babu, R. R. Dehoff, S. Pannala, S. Simunovic, M. K. Kirka, J. Turner and N. Carlson, Acta Materialia, 2016, Vol. 112, pp. 303-314CrossRefGoogle Scholar
  31. 31.
    J. Raplee, A. Plotkowski, M. Kirka, R. Dinwiddie, A. Okello, R. R. Dehoff and S. S. Babu, Sci. Rep. 2017, Vol. 7, 43554; CrossRefGoogle Scholar
  32. 32.
    I. Yadroitsev and I. Smurov, Physics Procedia, 2011, Vol. 12, pp. 264-270CrossRefGoogle Scholar
  33. 33.
    M. Groeber, E. Schwalbach, W. Musinski, P. Shade, S. Donegan, M. Uchic, D. Sparkman, T. Turner and J. Miller, JOM, 2018, Vol. 70, pp. 441-444CrossRefGoogle Scholar
  34. 34.
    W. Sames, K. Unocic, G. Helmreich; S. S. Babu; R. Dehoff; F. Medina, Additive manufacturing, 2016, Vol. 13, pp. 156-165CrossRefGoogle Scholar
  35. 35.
    W. Sames, K. Unocic, R. R. Dehoff, T. Lolla and S. S. Babu, Journal of Materials Research, 2014, Vol. 29, pp. 1920-1930CrossRefGoogle Scholar
  36. 36.
    Y. Ogawa, Science and Technology of Welding and Joining, 2011, Vol. 16, pp. 33-43CrossRefGoogle Scholar
  37. 37.
    S. Tsukamoto, Science and Technology of Welding and Joining, 2011, Vol. 16, pp. 33-43CrossRefGoogle Scholar
  38. 38.
    R. R. Dehoff, W. J. Sames, M. K. Kirka, H. Bilheux, A. S. Tremsin and S. S. Babu, Materials Science and Technology, 2015, Vol. 31, pp. 931-938CrossRefGoogle Scholar
  39. 39.
    J. Gockel, L. Sheridan, S. P, Barra, N. W. Klingbeil, J. Beuth, JOM, 2017, Vol. 69, pp. 2706-2710CrossRefGoogle Scholar
  40. 40.
    C. R. Clymer, J. Cagan, and J. Beuth, Journal of Mechanical Design, 2017, Vol. 139, 100907CrossRefGoogle Scholar
  41. 41.
    M. Tang, P. C. Pistorious, J. L. Beuth, Additive Manufacturing, 2017, Vol. 14, pp. 39-48CrossRefGoogle Scholar
  42. 42.
    D. Rosenthal, Welding Journal, 1941, Vol. 20, pp. 220-234Google Scholar
  43. 43.
    P. W. Fuerschbach, Welding Journal, 1996, Vol. 75, pp. 24s-34sGoogle Scholar
  44. 44.
    M. J. Aziz, Journal of Applied Physics, 1982, Vol. 53, pp. 1158-1168CrossRefGoogle Scholar
  45. 45.
    S. S. Babu, J. W. Elmer, J. M. Vitek, and S. A. David, Acta Materialia, 2002, Vol. 50, pp. 4763-4781CrossRefGoogle Scholar
  46. 46.
    A. Plotkowski, O. Rios, N. Sridharan, Z. Sims, K. Unocic, R. T. Ott, R. R. Dehoff, and S. S. Babu, Acta Materialia, 2017, Vol. 126, pp. 507-519CrossRefGoogle Scholar
  47. 47.
    J. O. Andersson, T. Helander, L. Hoglund, P. F. Shi and B. Sundman, CALPHAD, 2002, Vol. 26, pp. 273-312CrossRefGoogle Scholar
  48. 48.
    M. Gaumann, C. Bezencon, P. Canalis, and W. Kurz, Acta Materialia, 2001, 49: 1051-1062CrossRefGoogle Scholar
  49. 49.
    M. Y. Krasnoperov, R. R. G. M. Pieters and I. M. Richardson, Science and Technology of Welding and Joining, 2004, Vol. 9, pp. 501-506CrossRefGoogle Scholar
  50. 50.
    S. S. Babu, S. M. Kelly, M. Murugananth, R. P. Martukanitz, Surface Coating and Technology, 2006 Vol. 200, pp. 2663-2671CrossRefGoogle Scholar
  51. 51.
    S. S. Babu, R. P. Martukanitz, K. D. Parks, and S. A. David, Metallurgical and Materials Transactions A, 2002, 33A, 1189-1200CrossRefGoogle Scholar
  52. 52.
    C. Villafuerte, H. W. Kerr, and S. A. David, Materials Science and Engineering A, 1995, Vol. 194, pp.187-191CrossRefGoogle Scholar
  53. 53.
    J. H. Martin, B. D. Yahata, J. M. Hundley, J. A. Mayer, T. A. Schaedler and T. M. Pollock, Nature, 2017, Vol. 549, pp. 365-369CrossRefGoogle Scholar
  54. 54.
    O. M. Barabash, S. S. Babu, J. M. Vitek, S. A. David, J. -W. Park, J. A. Horton, G. E. Ice, and R. I. Barabash, J. App. Physics, 2004, Vol. 96, pp. 3673 – 3679Google Scholar
  55. 55.
    O. M. Barabash, S. S. Babu, S. A. David, J. M. Vitek and R. I. Barabash, Journal of Applied Physics, 2003, 94, No. 1., 738-742CrossRefGoogle Scholar
  56. 56.
    P. J. Withers and H. K. D. H. Bhadeshia, Materials Science and Technology, 2001, Vol. 17, pp. 366-375CrossRefGoogle Scholar
  57. 57.
    D. Wian, J. Xue, A. X. Zhang, Y. Li, N. Tamura, Z. Song and K. Chen, Scientific Reports, 2017, 7: 2859CrossRefGoogle Scholar
  58. 58.
    Y. M. Wang, T. Voisin, J. T. McKeown, J. Ye, N. P. Calta, Z. Li, Z. Zeng, Y. Zhang, W. Chen, T. T. Roehling, R. T. Ott, M. K. Santala, P. J. Depond, M. J. Matthews, A. V. Hamza and T. Zhu, Nature Materials, 2018, Vol. 17, pp. 63-71CrossRefGoogle Scholar
  59. 59.
    S.S. Babu: in Proc. Int. Conf. Solid–Solid Phase Transform. Inorg. Mater. M. Millitzer, G. Botton, L.-Q. Chen, J. How, C. Sinclair, and H. Zurob (eds.) TMS, 2015, pp. 1019–26Google Scholar
  60. 60.
    K.T. Makiewicz: MS Thesis, The Ohio State University, 2013Google Scholar
  61. 61.
    S. Fukumoto and W. Kurz, ISIJ International, 1999, Vol. 39, pp. 1270-1279CrossRefGoogle Scholar
  62. 62.
    J. A. Dantzig and M. Rappaz, “Solidification,” 2nd Edition, EPFL Press, Lausanne, 2016Google Scholar
  63. 63.
    S. S. Babu, International Materials Reviews, 2009, Vol. 54, pp. 333-367CrossRefGoogle Scholar
  64. 64.
    S. J. Jones and H. K. D. H. Bhadeshia, Acta Materialia, Vol. 45, pp. 2911-2920, 1997CrossRefGoogle Scholar
  65. 65.
    J. W. Christian, “The theory of transformations in metals and alloys v1 and v2,”1st Edition, Pergamon Press, Oxford, 2002Google Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2018

Authors and Affiliations

  • S. J. Foster
    • 1
    • 5
  • K. Carver
    • 3
    • 4
  • R. B. Dinwiddie
    • 3
    • 4
  • F. ListIII
    • 3
    • 4
  • K. A. Unocic
    • 3
  • A. Chaudhary
    • 6
  • S. S. Babu
    • 1
    • 2
    • 4
    Email author
  1. 1.Department of Materials Science and EngineeringThe University of TennesseeKnoxvilleUSA
  2. 2.Department of Mechanical and Aerospace and Biomedical EngineeringThe University of TennesseeKnoxvilleUSA
  3. 3.Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeUSA
  4. 4.Manufacturing Demonstration FacilityOak Ridge National LaboratoryOak RidgeUSA
  5. 5.Oerlikon AM USCharlotteUSA
  6. 6.Applied Optimization IncDaytonUSA

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