Laser powder bed fusion (LPBF) is a technique that is used to manufacture the parts with high relative density and mechanical properties as well as to that of conventional approaches i.e. casting. As the complex interaction between the laser and the powder in LPBF, it has some flaws like pores, micro-cracks, and distortion during the built. Inconel-713LC is a low carbon (LC) nickel-based superalloy, generally produced by casting, which is widely used in hot section components of gas turbine engines. The selection of materials for gas turbines is critical to obtain high efficiency and reliability, especially for the components located in the high-temperature service section where the flow of hot gases imposes severe operating conditions. To withstand the loading conditions at high temperatures (500–915◦C), it’s considered as a non-weldable alloy as it has a high percentage of Al+Ti compared to that of Inconel 718. This study focuses on the mechanical properties, microstructure, and phases of IN713LC for the as-built specimen and after the heat-treatment. In this study, experimental results show that the tensile strength and elongation of LPBF printed IN713LC tensile bar are higher than those made by casting. The yield strength of 791 MPa, the ultimate strength of 995 MPa, elongation of 12%, and relative density of the specimen approximately 99.98% is achieved. The crack density is also reduced to a lower number to 0.11% per mm². It’s concluded that there are two kinds of micro-cracks, one is called solidification cracking which due to the composition effect, and the other is ductility dip cracking (DDC) which is due to reheating of the subsequent layer because of grain boundary slides and causes micro-cracking. Also, it’s concluded that heat treatment of IN713LC processed by LPBF is as it reduces mechanical properties. There are two possible reasons for that, one is an increase of the grain size after heat treatment, and the other possible reason is strain age cracking (SAC) which occurs in Ni-based after the heat treatment as it causes more cracks for non-weldable alloys or increases the size of already existing cracks. According to [1], Hot Isostatic Pressing (HIP) is the possible way to improve the mechanical properties as it could close the cracks and also close the small pores that would cause a reduction in mechanical properties.

[1] M. L. Montero-Sistiaga, S. Pourbabak, J. Van Humbeeck, D. Schryvers, and K. Vanmeensel, "Microstructure and mechanical properties of Hastelloy X produced by HP-SLM (high power selective laser melting)," Materials & Design, vol. 165, p. 107598, 2019.
[2] A. J. Pinkerton and L. Li, "Modelling the geometry of a moving laser melt pool and deposition track via energy and mass balances," Journal of Physics D: Applied Physics, vol. 37, no. 14, p. 1885, 2004.
[3] D. Gu, W. Meiners, Y.-C. Hagedorn, K. Wissenbach, and R. Poprawe, "Bulk-form TiCx/Ti nanocomposites with controlled nanostructure prepared by a new method: selective laser melting," Journal of Physics D: Applied Physics, vol. 43, no. 29, p. 295402, 2010.
[4] J.-P. Kruth, M.-C. Leu, and T. Nakagawa, "Progress in additive manufacturing and rapid prototyping," CIRP Annals-Manufacturing Technology, vol. 47, no. 2, pp. 525-540, 1998.
[5] K. Osakada and M. Shiomi, "Flexible manufacturing of metallic products by selective laser melting of powder," International Journal of Machine Tools and Manufacture, vol. 46, no. 11, pp. 1188-1193, 2006.
[6] D. L. Prakash, M. Walsh, D. Maclachlan, and A. Korsunsky, "Crack growth micro-mechanisms in the IN718 alloy under the combined influence of fatigue, creep and oxidation," International Journal of Fatigue, vol. 31, no. 11-12, pp. 1966-1977, 2009.
[7] H. Qi, M. Azer, and A. Ritter, "Studies of standard heat treatment effects on microstructure and mechanical properties of laser net shape manufactured Inconel 718," Metallurgical and Materials Transactions A, vol. 40, no. 10, pp. 2410-2422, 2009.
[8] M. Srivastava and M. Mishra, "3D Printing: Additive Manufacturing."
[9] J. Edgar and S. Tint, "Additive manufacturing technologies: 3D printing, rapid prototyping, and direct digital manufacturing," Johnson Matthey Technology Review, vol. 59, no. 3, pp. 193-198, 2015.
[10] W. E. Frazier, "Metal additive manufacturing: a review," Journal of Materials Engineering and Performance, vol. 23, no. 6, pp. 1917-1928, 2014.
[11] L. N. Carter, "Selective laser melting of nickel superalloys for high temperature applications," University of Birmingham, 2013.
[12] M. J. Donachie and S. J. Donachie, Superalloys: a technical guide. ASM international, 2002.
[13] Z. Zhu, H. Basoalto, N. Warnken, and R. Reed, "A model for the creep deformation behaviour of nickel-based single crystal superalloys," Acta Materialia, vol. 60, no. 12, pp. 4888-4900, 2012.
[14] C. Sims, "T.–Stoloff, NS–Hagel, WC: Superalloys II," ed: John Wiley & Sons, Inc., USA, 1987.
[15] M. Henderson, D. Arrell, R. Larsson, M. Heobel, and G. Marchant, "Nickel based superalloy welding practices for industrial gas turbine applications," Science and technology of welding and joining, vol. 9, no. 1, pp. 13-21, 2004.
[16] N. J. Harrison, "Selective laser melting of nickel superalloys: solidification, microstructure and material response," Ph.D. dissertation, University of Sheffield, 2016.
[17] J. C. Lippold, S. D. Kiser, and J. N. DuPont, Welding metallurgy and weldability of nickel-base alloys. John Wiley & Sons, 2011.
[18] S. Kou, "Welding metallurgy," New Jersey, USA, pp. 431-446, 2003.
[19] J. Risse and C. Broeckmann, "Additive manufacturing of nickel-base superalloy IN738LC by laser powder bed fusion," Lehrstuhl für Lasertechnik2019.
[20] M. Rowe, "Ranking the resistance of wrought superalloys to strain-age cracking," Welding journal, vol. 85, no. 2, pp. 60-71, 2006.
[21] D. Grange, J.-D. Bartout, B. Macquaire, and C. Colin, "Processing a non-weldable Nickel-base superalloy by Selective Laser Melting: role of the shape and size of the melt pools on solidification cracking," Materialia, 2020.
[22] M. Rappaz, J. M. Drezet, and M. Gremaud, "A new hot-tearing criterion," Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science, vol. 30, no. 2, pp. 449-455, 1999.
[23] C. Wei, H. Bor, C. Ma, and T. Lee, "A study of IN-713LC superalloy grain refinement effects on microstructure and tensile properties," Materials chemistry and physics, vol. 80, no. 1, pp. 89-93, 2003.
[24] T. Maccagno, A. Koul, J.-P. Immarigeon, L. Cutler, R. Allem, and G. L’esperance, "Microstructure, creep properties, and rejuvenation of service-exposed alloy 713C turbine blades," Metallurgical Transactions A, vol. 21, no. 12, pp. 3115-3125, 1990.
[25] B. B. Galizoni, A. A. Couto, and D. A. P. Reis, "Heat treatments effects on nickel-based superalloy inconel 713C," Metals, vol. 9, no. 1, p. 47, 2019.
[26] L. Koll, P. Tsipouridis, and E. Werner, "Preparation of metallic samples for electron backscatter diffraction and its influence on measured misorientation," Journal of microscopy, vol. 243, no. 2, pp. 206-219, 2011.
[27] Z. Wang, K. Guan, M. Gao, X. Li, X. Chen, and X. Zeng, "The microstructure and mechanical properties of deposited-IN718 by selective laser melting," Journal of alloys and compounds, vol. 513, pp. 518-523, 2012.
[28] V. Popovich, E. Borisov, A. Popovich, V. S. Sufiiarov, D. Masaylo, and L. Alzina, "Functionally graded Inconel 718 processed by additive manufacturing: Crystallographic texture, anisotropy of microstructure and mechanical properties," Materials & Design, vol. 114, pp. 441-449, 2017.
[29] D. F. Heaney, Handbook of metal injection molding. Woodhead Publishing, 2018.
[30] H. Wang et al., "Selective laser melting of the hard-to-weld IN738LC superalloy: Efforts to mitigate defects and the resultant microstructural and mechanical properties," Journal of Alloys and Compounds, vol. 807, p. 151662, 2019.
[31] W. Zhou et al., "Inhibition of cracking by grain boundary modification in a non-weldable nickel-based superalloy processed by laser powder bed fusion," Materials Science and Engineering: A, vol. 791, p. 139745, 2020.
[32] P. Gao et al., "Cracking behavior and control of β-solidifying Ti-40Al-9V-0.5 Y alloy produced by selective laser melting," Journal of Materials Science & Technology, vol. 39, pp. 144-154, 2020.
[33] R. Rosenthal and D. R. F. West, "Continuous γ′ precipitation in directionally solidified IN738 LC alloy," Materials science and technology, vol. 15, no. 12, pp. 1387-1394, 1999.
[34] A. Chamanfar, M. Jahazi, A. Bonakdar, E. Morin, and A. Firoozrai, "Cracking in fusion zone and heat affected zone of electron beam welded Inconel-713LC gas turbine blades," Materials Science and Engineering: A, vol. 642, pp. 230-240, 2015.
[35] L. N. Carter, M. M. Attallah, and R. C. Reed, "Laser powder bed fabrication of nickel-base superalloys: influence of parameters; characterisation, quantification and mitigation of cracking," Superalloys, vol. 2012, pp. 577-586, 2012.
[36] Systematic Approach for Reducing Micro-Crack Formation in Inconel 713LC Components Fabricated by Laser Powder Bed Fusion" Hung-Yu Wang,Yu-Lung Lo,Hong-Chuong Tran, Trong-Nhan Le and M. Mohsin Raza"