Journals →  Tsvetnye Metally →  2018 →  #7 →  Back

ArticleName Control of structure formation in selective laser melting process
DOI 10.17580/tsm.2018.07.11
ArticleAuthor Sufiyarov V. Sh., Borisov E. V., Polozov I. A., Masailo D. V.

Saint Petersburg Polytechnic University of Peter the Great, Saint Petersburg, Russia:

V. Sh. Sufiyarov, Leading Researcher of the National Technology Initiative Center of Excellence in "Advanced Manufacturing Technologies" (NTI Center), e-mail:
E. V. Borisov, Researcher of the NTI Center
I. A. Polozov, Researcher of the NTI Center
D. V. Masailo, Researcher of the NTI Center


Additive technologies are of great interest for the manufacture of metal products as they allow the development of complex structures with high mechanical characteristics. At the same time, the question of the possibility of controlling the process of structure formation in products in the process of its production remains topical. Of particular interest is the possibility of simultaneously creating local sections in the product with a given microstructure and properties. A complex study of the influence of technological parameters of the selective laser melting process on the structure and properties of samples from the Inconel 718 alloy is presented. The results of studies of the mechanical properties of compact samples made at different layer thicknesses, both in the initial state and after hot isostatic pressing and heat treatment are presented. The results of a study of the possibility of creating samples with a variable microstructure depending on the parameters of the selective laser melting process are presented. Samples with a variable structure are produced and investigated, in which the regions with finely dispersed equiaxed grains and large columnar grains are programmatically present. At the boundary of these regions, mutual penetration of large and small grains is observed. The EBSD analysis showed that a change in the thickness of the layer and the technological parameters of the selective laser melting process makes it possible to locally change the size and morphology of the grains of the material. When using a large layer thickness, the directional crystallization mode and the formation of columnar grains are possible. It is shown that after the heat treatment and hot isostatic pressing, the differences in the structure and mechanical properties between the regions are preserved.
The work was carried out within the framework of the implementation of the federal target program “Research and development in priority areas of development of Russia's scientific and technological complex for 2014–2020”, the unique identifier of the project RFMEFI57817X0245.

keywords Additive production, selective laser melting, additive technologies, nickel superalloy, functional gradient material, microstructure control, heat treatment, powder metallurgy

1. Wohlers Т. Wohlers Report 2017: Additive Manufacturing and 3D Printing State of the Industry. Annual Worldwide Progress Report. Colorado : Wohlers Associates Inc., 2017.
2. Holzweissig M. J. et al. Microstructural characterization and mechanical performance of hot work tool steel processed by selective laser melting. Metallurgical and Materials Transactions B. 2015. Vol. 46, No. 2. pp. 545–549.
3. Popovich A., Sufiiarov V. Metal Powder Additive Manufacturing. New Trends in 3D Printing. Chapter: 10. InTech, 2016. pp. 215–236.
4. Popovich A., Sufiiarov V., Polozov I., Borisov E., Masaylo D. Additive manufacturing of individual implants from titanium alloy. METAL 2016. 25th Anniversary International Conference on Metallurgy and Materials. Conference Proceedings. 2016. pp. 1504–1508.
5. Paulonis D. F., Schirra J. J. Alloy 718 at Pratt & Whitney-Historical perspective and future challenges. Superalloys 718, 625, 706 and Various Derivatives. 2001. pp. 13–23.
6. Abraham A. K., Sridhar V. G. Materials, Design and Manufacturing Technologies for Orthopaedic Biomaterials: A Review. International Journal of Applied Engineering Research. 2015. Vol. 10, Iss. 19. pp. 40059–40062.
7. Frazier W. E. Metal additive manufacturing: A review. Journal of Materials Engineering and Performance. 2014. Vol. 23, No. 6. pp. 1917–1928.
8. Sufiyarov V. Sh., Popovich A. A., Borisov E. V., Polozov I. A. Evolution of structure and properties of heat-resistant nickel alloy after selective laser melting, hot isostatic pressing and heat treatment. Tsvetnye Metally. 2017. No. 1. pp. 77–82.
9. Amato К. N. et al. Microstructures and mechanical behavior of Inconel 718 fabricated by selective laser melting. Acta Materialia. 2012. Vol. 60, No. 5. pp. 2229– 2239.
10. Jia Q., Gu D. Selective laser melting additive manufacturing of Inconel 718 superalloy parts: Densification, microstructure and properties. Journal of Alloys and Compounds. 2014. Vol. 585. pp. 713–721.
11. Wauthle R. et al. Effects of build orientation and heat treatment on the microstructure and mechanical properties of selective laser melted Ti6A14V lattice structures. Additive Manufacturing. 2015. Vol. 5. pp. 77–84.
12. Smelov V. G., Sotov A. V., Agapovichev A. V. Study of structures and mechanical properties of products manufactured via selective laser sintering of 316L steel powder. Chernye Metally. 2016. No. 9. pp. 61–65.
13. Ströner J., Terock M., Glatzel U. Mechanical and Microstructural Investigation of Nickel-Based Superalloy IN718 Manufactured by Selective Laser Melting (SLM). Advanced Engineering Materials. 2015. Vol. 17, No. 8. pp. 1099–1105.
14. Sufiiarov V. Sh., Popovich A. A., Borisov E. V., Polozov I. A. Selective laser melting of heat-resistant Ni-based alloy. Non-ferrous Metals. 2015. No.1. pp. 32–35.
15. Sufiiarov V. Sh., Popovich A. A., Borisov E. V., Polozov I. A. Layer thickness influence on the Inconel 718 alloy microstructure and properties under selective laser melting. Tsvetnye Metally. 2016. No. 1. pp. 81–86.
16. Meier H., Haberland C. Experimental studies on selective laser melting of metallic parts. Materialwissenschaft und Werkstofftechnik. 2008. Vol. 39, No. 9. pp. 665–670.
17. Pedron J. P., Pineau A. The effect of microstructure and environment on the crack growth behaviour of Inconel 718 alloy at 650 oС under fatigue, creep and combined loading. Materials science and engineering. 1982. Vol. 56, No. 2. pp. 143–156.
18. Bai S., Yang L., Liu J. Manipulation of microstructure in laser additive manufacturing. Applied Physics A. 2016. Vol. 122, No. 5. pp. 1–5.
19. Niendorf T., Brenne F., Schaper M., Reimche W. Labelling additively manufactured parts by microstructural gradation — advanced copy-proof design. Rapid Prototyping Journal. 2016. Vol. 22, No. 4. pp. 630–635.
20. Agapovichev A. V. et al. Selective laser melting of titanium alloy: investigation of mechanical properties and microstructure. IOP Conference Series: Materials Science and Engineering. 2016. Vol. 156, No. 1. pp. 012031.
21. Popovich V. A., Borisov E. V., Popovich A. A., Sufiiarov V. Sh., Masaylo D. V., Alzina L. Impact of heat treatment on mechanical behaviour of Inconel 718 processed with tailored microstructure by selective laser melting. Materials & Design. 2017. Vol. 131. pp. 12–22.
22. Golod V. M., Sufiiarov V. S. The evolution of structural and chemical heterogeneity during rapid solidolization at gas atomization. IOP Conference Series: Materials Science and Engineering. 2017. Vol. 192 (1). DOI: 10.1088/1757-899X/192/1/012009.
23. Baufeld B. Mechanical properties of Inconel 718 parts manufactured by shaped metal deposition (SMD). Journal of materials engineering and performance. 2012. Vol. 21, No. 7. pp. 1416–1421.

Full content Control of structure formation in selective laser melting process