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Additive manufacturing of nickel-based superalloy Inconel 718 by selective electron beam melting: Processing window and microstructure

Published online by Cambridge University Press:  11 August 2014

Harald Ernst Helmer ,
Carolin Körner  and
Robert Friedrich Singer
Harald Ernst Helmer*
Affiliation:
Zentralinstitut für Neue Materialien und Prozesstechnik (ZMP), University of Erlangen-Nuernberg, Fürth 90762, Germany
Carolin Körner
Affiliation:
Department of Materials Science, Chair of Metals Science and Technology, University of Erlangen-Nuernberg, Erlangen 91058, Germany
Robert Friedrich Singer
Affiliation:
Department of Materials Science, Chair of Metals Science and Technology, University of Erlangen-Nuernberg, Erlangen 91058, Germany
*
a)Address all correspondence to this author. e-mail: harald.e.helmer@fau.de
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Abstract

Cube-shaped IN718 samples were produced by selective electron beam melting (SEBM) with varying beam power, deflection speed, and beam spot size. Process parameter windows were identified where fully dense samples are obtained with no surface unevenness. High deflection speeds were demonstrated to result in smaller demand of area energy. This result is explained by the reduced time for heat dissipation into the substrate during hatching. The grain structure was strongly affected by SEBM process parameters. Under certain conditions, epitaxial growth over many layers and well-developed columnar grain structures were obtained with a polycrystalline substrate plate. A more defocused beam led to a lower melt pool temperature and shallower melt pool geometry where maximum temperature gradients and solidification rates were more or less in parallel with the building direction and primary dendrite arm orientation. These conditions help to suppress grain nucleation ahead of the nucleation front as vigorous melt movement, fragmentation of dendrites, and tertiary arm growth are suppressed.

Type
Articles
Information
Journal of Materials Research , Volume 29 , Issue 17: Focus Issue: The Materials Science of Additive Manufacturing , 14 September 2014 , pp. 1987 - 1996
Copyright
Copyright © Materials Research Society 2014 

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References

REFERENCES

Hopkinson, N., Hague, R., and Dickens, P.: Rapid Manufacturing: An Industrial Revolution for the Digital Age, 1st ed. (Wiley, Camberley, England, 2006).Google Scholar
Blackwell, P.: The mechanical and microstructural characteristics of laser-deposited IN718. J. Mater. Process. Technol. 170(1–2), 240 (2005).Google Scholar
Strondl, A., Fischer, R., Frommeyer, G., and Schneider, A.: Investigations of MX and γ′/γ″ precipitates in the nickel-based superalloy 718 produced by electron beam melting. Mater. Sci. Eng., A 480(1–2), 138 (2008).CrossRefGoogle Scholar
Strondl, A., Palm, M., Gnauk, J., and Frommeyer, G.: Microstructure and mechanical properties of nickel based superalloy IN718 produced by rapid prototyping with electron beam melting (EBM). Mater. Sci. Technol. 27(5), 876 (2009).CrossRefGoogle Scholar
Strondl, A., Milenkovic, S., Schneider, A., Klement, U., and Frommeyer, G.: Effect of processing on microstructure and physical properties of three nickel-based superalloys with different hardening mechanisms. Adv. Eng. Mater. 14(7), 427 (2012).CrossRefGoogle Scholar
Amato, K.N., Gaytan, S.M., Murr, L.E., Martinez, E., Shindo, P.W., Hernandez, J., Collins, S., and Medina, F.R.: Microstructures and mechanical behavior of Inconel 718 fabricated by selective laser melting. Acta Mater. 60(5), 2229 (2012).Google Scholar
Wang, Z., Guan, K., Gao, M., Li, X., Chen, X., and Zeng, X.: The microstructure and mechanical properties of deposited-IN718 by selective laser melting. J. Alloys Compd. 513(0), 518 (2012).CrossRefGoogle Scholar
Heinl, P., Müller, L., Körner, C., Singer, R.F., and Müller, F.A.: Cellular Ti–6Al–4V structures with interconnected macro porosity for bone implants fabricated by selective electron beam melting. Acta Biomater. 4(5), 1536 (2008).CrossRefGoogle ScholarPubMed
Zhao, X., Chen, J., Lin, X., and Huang, W.: Study on microstructure and mechanical properties of laser rapid forming Inconel 718. Mater. Sci. Eng., A 478(1–2), 119 (2008).Google Scholar
Qi, H., Azer, M., and Ritter, A.: Studies of standard heat treatment effects on microstructure and mechanical properties of laser net shape manufactured INCONEL 718. Metall. Mater. Trans. A 40(10), 2410–2422 (2009).Google Scholar
Klassen, A., Scharowsky, T., and Körner, C.: Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods. J. Phys. D: Appl. Phys. 47(27), 275 (2014).CrossRefGoogle Scholar
Carslaw, H.S. and Jaeger, J.C.: Conduction of Heat in Solids, 2nd ed. (Oxford University Press, New York, 1959), pp. 58–62.Google Scholar
Pottlacher, G., Hosaeus, H., Kaschnitz, E., and Seifter, A.: Thermophysical properties of solid and liquid Inconel 718 alloy. Scand. J. Metall. 31(3), 161 (2002).Google Scholar
Ito, R., Andreo, P., and Tabata, T.: Reflection ratios of electrons and photons from solids. Bull. Univ. Osaka Prefect., Ser. A 41(2), 69 (1992).Google Scholar
Tabata, T., Andreo, P., and Shinoda, K.: Fractional energies of backscattered electrons and photon yields by electrons. Radiat. Phys. Chem. 54(1), 11 (1999).Google Scholar
Walton, D. and Chalmers, B.: The origin of the preferred orientation in the columnar zone of ingots. Trans. Metall. Soc. AIME 215(6), 1 (1959).Google Scholar
Gäumann, M., Bezençon, C., Canalis, P., and Kurz, W.: Single-crystal laser deposition of superalloys: Processing–microstructure maps. Acta Mater. 49(6), 1051 (2001).CrossRefGoogle Scholar
Thijs, L., Verhaeghe, F., Craeghs, T., Humbeeck, J.V., and Kruth, J.P.: A study of the microstructural evolution during selective laser melting of Ti-6Al-4V. Acta Mater. 58(9), 3303 (2010).CrossRefGoogle Scholar
Gäumann, M., Henry, S., Cléton, F., Wagnière, J-D., and Kurz, W.: Epitaxial laser metal forming: Analysis of microstructure formation. Mater. Sci. Eng., A 271(1–2), 232 (1999).CrossRefGoogle Scholar
Trivedi, R. and Kurz, W.: Dendritic growth. Int. Mater. Rev. 39(2), 49 (1994).CrossRefGoogle Scholar
Rappaz, M., David, S.A., Vitek, J.M., and Boatner, L.A.: Development of microstructures in Fe−15Ni−15Cr single crystal electron beam welds. Metall. Mater. Trans. A 20(6), 1125 (1989).Google Scholar
Rappaz, M., David, S.A., Vitek, J.M., and Boatner, L.A.: Analysis of solidification microstructures in Fe-Ni-Cr single-crystal welds. Metall. Mater. Trans. A 21(6), 1767 (1990).CrossRefGoogle Scholar
Mokadem, S., Bezençon, C., Hauert, A., Jacot, A., and Kurz, W.: Laser repair of superalloy single crystals with varying substrate orientations. Metall. Mater. Trans. A 38(7), 1500 (2007).Google Scholar