Studying the possibility of selective laser sintering technology application for aerodynamic models manufacturing

DOI: 10.34759/vst-2023-2-46-50

Аuthors

Shuvalova A. M.^*, Filimonov A. S.^**, Galinovskii A. L.^***

Bauman Moscow State Technical University, MSTU, 5, bldg. 1, 2-nd Baumanskaya str., Moscow, 105005, Russia

*e-mail: nuts97@inbox.ru
**e-mail: alexf72@mail.ru
***e-mail: galcomputer@mail.ru

Abstract

Technologies of layer-by-layer laser sintering by the SLS-printing method are being increasingly employed in modern mechanical engineering and instrumentation. The gist of the technology consists in layer-by-layer sintering of powder materials (polyamides, plastics) using a laser beam.

Relatively low labor intensity and cost, as well as the achievable speed of products manufacturing allows applying this technology to aerodynamic models creation used for experimental testing of aerospace engineering products. However, the development of these technologies is hindered by the poor studies of the internal structure of the parts’ material.

There is an assumption based on the study of the outer layer of printed parts that a high porosity presents in the parts, caused by incomplete melting of all powder particles. This effect of incomplete sintering is visible on the outer surface. The problem lies in the fact that when sintering powder particles with a laser, neighboring, i.e. nearby particles that do not completely melt, forming a kind of a"relief" of the surface, are baked to the outer molten layer. It is obvious that such surface is not set in advance at the design stage, and the formed surface layer of stuck particles can be called undesirable. The external roughness control is especially up-to-date when creating aerodynamic models, since the external structure of the product surface may greatly affect the structure of the gas flow and the change in aerodynamic characteristics. The study of this layer and the roughness parameters will help designers to set and evaluate the necessary design requirements.

The research conduction is based on the results of a series of experiments performed with the EOS FORMIGA P110 SLS printing unit, in which laser is the main heat source with a power of 200 W-1 kW. The PA 2200 polymer was used for the samples production.

One of the problems while the research conducting is the impossibility of cutting samples or obtaining sections by mechanical or other methods without damaging the material structure. To solve it, an approach was adopted, according to which the operation of the installation was «emergently» terminated until the next layer of powder was applied. In other words, the newly obtained sample layer was not being filled with powder to form a new subsequent layer. It is possible to fulfill this by the printing emergency stoppage. Thus, it provided an opportunity to study the surface of the sample by the microscopy and measuring the roughness parameters of the formed surface. After processing the obtained images, the inference is being drawn that the internal structure is rather homogeneous and differs significantly from the outer layers of the samples. The outer layer of the products is of high level of roughness, which limits the possibility of their application in the field of aerodynamics. The article presents possible options for improving the surface layer of products.

The conclusion is made that the technology of selective laser sintering is utterly promising for creating aerodynamic models, provided that recommendations on improving characteristics of the outer surface roughness will be issued.

Keywords:

laser sintering, SLS printer, 3d printing, aerodynamic models, aerodynamic experiment

References

1. Mikrin E.A. Kosmicheskaya tekhnika i tekhnologii, 2017, no. 1(16), pp. 5–11.
2. Bourell D., Watt T., Leigh D.K., Fulcher B. Performance limitations in polymer laser sintering. Physics Procedia, 2014, vol. 56, pp. 147–156. DOI: 10.1016/j.phpro.2014.08.157
3. Badanina Yu.V., Galinovskii A.L., Golubev E.S. et al. Tekhnologiya selektivnogo lazernogo spekaniya v proizvodstve izdelii raketno-kosmicheskoi tekhniki (Technology of selective laser sintering in the production of rocket and space technology products), Moscow, MGTU im. Baumana, 2019, 37 p.
4. Galinovskii A.L., Golubev E.S., Kobernik N.V., Filimonov A.S. Additivnye tekhnologii v proizvodstve izdelii aerokosmicheskoi tekhniki (Additive technologies in the production of aerospace engineering products), Moscow, Yurait, 2023, 115 p. URL: https://urait.ru/bcode/518641
5. Izdeliya, poluchennye metodom additivnykh tekhnologicheskikh protsessov. Terminy i opredeleniya. GOST R 57911-2017 (Additive manufacturing products. Terminology, State Standard 121003-76), Moscow, Standartinform, 2018, 8 p.
6. Gibson I., Rosen D., Stucker B. Additive manufacturing technologies: 3D printing, rapid prototyping, and direct digital manufacturing. 2nd ed. New York, Springer-Verlag, 2015, 519 p. DOI: 10.1007/978-1-4939-2113-3
7. Shachnev S.Yu., Zaitsev A.M. Ritm: Remont. Innovatsii. Tekhnologii. Modernizatsiya, 2012, no. 6(74), pp. 34–36.
8. Korolev A.N., Tarasov V.A., Baskakov V.D. et al. Materialy XLIII Akademicheskie chteniya po kosmonavtike (29 January — 1 February 2019; Moscow), Moscow, MGTU im. N.E. Baumana, 2019, vol. 2, pp. 188-189.
9. Kok Y.H., Tan X., Wang P. et al. Anisotropy and heterogeneity of microstructure and mechanical properties in metal additive manufacturing: A critical review. Materials & Design, 2018, vol. 139, pp. 565–586. DOI: 10.1016/j.matdes.2017.11.021
10. Shekhovtsov A.A. Karpova N.P. Nauchno-metodicheskii elektronnyi zhurnal «Kontsept», 2015, vol. 13, pp. 141-145. URL: http://e-koncept.ru/2015/85029.htm
11. Khatuntseva O.N., Shuvalova A.M. On Additional «Multi-Scale» Similarity Criteria for Experimental Work-Out of Aerospace Engineering Products. Aerospace MAI Journal, 2023, vol. 30, no. 1, pp. 91-97. DOI: 34759/vst-2023-1-91-97
12. Flodberg G., Petterson H., Yang L. Pore analysis and mechanical performance of selective laser sintered objects. Additive Manufacturing, 2018, vol. 24, pp. 307-315. DOI: 10.1016/j.addma.2018.10.001
13. Baeva L.S., Marinin A.A. Vestnik MGTU. Trudy Murmanskogo gosudarstvennogo tekhnicheskogo universiteta, 2014, vol. 17, no. 1, pp. 7-12.
14. Additivnye tekhnologicheskie protsessy. Bazovye printsipy. Chast’ 1. Terminy i opredeleniya. GOST R 57558-2017 (Additive manufacturing — General principles — Terminology, IDT Part 1. Terms and definitions, ISO/ASTM 52900:2015), Moscow, Standartinform, 2020, 16 p.
15. Mikhalev P.A., Filimonov A.S., Korolev A.N., Shuvalova A.M. Materialy XLIII Akademicheskie chteniya po kosmonavtike (29 January — 1 February 2019; Moscow), Moscow, MGTU im. N.E. Baumana, 2019, vol. 2, pp. 189-190.
16. Majewski C., Zarringhalam H., Hopkinson N. Effect of the degree of particle melt on mechanical properties in selective laser-sintered Nylon-12 parts. Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture, 2008, vol. 222, no. 9, pp. 1055-1064. DOI: 10.1243/09544054JEM1122
17. Kosilova A.G., Meshcheryakov R.K. (ed.) Spravochnik tekhnologa-mashinostroitelya. V 2-kh t. (Handbook of a machine-building technologist. In 2 vols), 4th ed. Moscow, Mashinostroenie, 1986. Vol. 1, 656 p.
18. Parshev S.N., Ivannikov A.Yu. (comp.) Issledovanie parametrov sherokhovatosti poverkhnosti (Investigation of surface roughness parameters), Volgograd, IUNL VolgGTU, 2010, 14 p.
19. Aristov A.I., Kudryashov B.A., Yandulova O.V. Sherokhovatost’ poverkhnosti (Surface roughness), Moscow, MADI, 2015, 32 p.
20. Sherokhovatost’ poverkhnosti. Parametry, kharakteristiki i oboznacheniya. GOST 2789-73 (Surface roughness. Parameters and characteristics, State Standard 2789-73), Moscow, Standartinform, 2018, 7 p.
21. Zaplatin V.N., Sapozhnikov Yu.I., Dubov A.V., Dukhneev E.M. Osnovy materialovedeniya: metalloobrabotka (Fundamentals of Materials Science: metalworking). 8th ed. Moscow, Izdatel’skii tsentr «Akademiya», 2017, 272 p.