Controlled surface roughness of AlSi10Mg alloy produced by LPBF for aerospace heat exchange elements


Аuthors

Basov A. A.1*, Korobov K. S.2**, K. , Nikolaev I. A.2, Ripetskii A. V.2***

1. S. P. Korolev Rocket and Space Corporation «Energia», 4A Lenin Street, Korolev, Moscow area, 141070, Russia
2. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: sgcherkasov@yandex.ru
**e-mail: korobovks@mai.ru
***e-mail: a.ripetskiy@mail.ru

Abstract


This study investigates the controlled surface roughness of heat exchange components fabricated from AlSi10Mg alloy using Laser Powder Bed Fusion (LPBF) technology specifically for aerospace applications. One significant challenge in additive manufacturing for aerospace systems is achieving precision surface roughness without extensive post-processing, particularly for internal channels where cleaning powder residues is complex and costly. The present research addresses this issue by exploring laser contouring strategies to realize targeted roughness levels directly through the manufacturing process. A comprehensive experimental program was undertaken, systematically varying critical LPBF parameters including laser power (P), scanning speed (V), and layer thickness (LT). Detailed statistical analysis revealed that layer thickness (LT) exerted the most significant influence on final roughness outcomes, followed by laser power (P) and scanning speed (V). The LPBF process was segmented into coarse and fine treatment stages to optimize roughness characteristics effectively. Through precise fine-treatment parameter adjustments, an optimal linear energy density (LED) of approximately 1,309 J/mm was identified, dramatically reducing surface roughness values. Minimum roughness values achieved were Sa = 5,45 μm for upskin surfaces and Sa = 7,232 μm for downskin surfaces at a 20 μm layer thickness. Median roughness measurements, serving as more representative indicators of typical performance, were recorded at Sa = 9,781 μm for upskin and Sa = 12,859 μm for downskin surfaces at 40 μm layer thickness. Maximum roughness levels reached Sa = 68,217 μm for downskin surfaces at an 80 μm thickness. The research further identified specific critical surface inclination angles ranging between 28° and 40°, at which roughness increased sharply, by approximately 6–10 times. These critical angles are crucial considerations in aerospace component design, impacting heat transfer and fluid flow efficiency. The study conclusively demonstrated that it is feasible to tailor surface roughness to specific functional requirements, offering significant advantages for the thermal management systems of spacecraft. The critical role of volumetric energy density (VED), in combination with pre-optimized linear energy density, was underscored as essential for achieving reproducible, precisely controlled surface textures. Future work aims to expand on these findings by evaluating variations in laser beam diameters and employing advanced scanning strategies. 

Keywords:

additive manufacturing, Laser Powder Bed Fusion, heat exchangers, controlled roughness, volumetric energy density

References

  1. Gushchin VN. Fundamentals of spacecraft design. Moscow. Mashinostroenie; 2003. 272 p. (In Russ.).
  2. Malozemov VV. Thermal regime of spacecraft. Moscow. Mashinostroenie; 1980. 232 p. (In Russ.).
  3. Kudryavtseva NS. Fundamentals of designing effective spacecraft temperature control. Moscow: MAI; 2012. 226 p. (In Russ.).
  4. Galinovskii AL, Golubev ES, Kobernik NV et al. Additive technologies in the manufacture of aerospace products. Moscow: Yurait; 2020. 115 p. (In Russ.).
  5. Krokhin AD. Additive technologies in the aluminum industry. Algoritm uspekha. 2017;(1):26–29. (In Russ.).
  6. Mal'tsev IE, Basov AA, Borisov MA et al. Analysis of the results of complex tests of an experimental spacepurpose heat exchanger manufactured by selective laser fusion. Elektrometallurgiya. 2021;(6). (In Russ.).
  7. Avtushenko AA, Basov AA, Mal'tsev IE et al. A method of designing heat exchange devices for electronic equipment adapted to additive manufacturing technologies. Tsvetnye metally. 2019;(12). (In Russ.).
  8. Mal'tsev IE, Basov AA, Borisov MA et al. Investigation of the properties of a fragment of the hydraulic circuit of a spacecraft obtained by methods of additive technologies. Spravochnik. Inzhenernyi zhurnal. 2020(4):11–19. (In Russ.).
  9. Poruchikova YuV, Yakupova NS, Basov AA et al. Assessment of the corrosion resistance of a typical fragment of the hydraulic circuit of the spacecraft thermal management system synthesized by selective laser fusion. Vestnik MAI. 2023;(4). (In Russ.).
  10. Koziner YuD, Mal'tsev IE, Basov AA et al. Targeted ultrasonic cleaning of inaccessible internal surfaces of heat exchange devices manufactured using additive technologies. Tsvetnye metally. 2022;(9):78–83. (In Russ.).
  11. Koziner YuD, Basov AA, Kravtsov DA et al. The method of two-level ultrasonic cleaning of hidden cavities of heat exchange devices obtained by methods of additive technologies. Elektrometallurgiya. 2024;(6):21–33. (In Russ.).
  12. Nismath VH, Beytullah A, Jaggers D et al. On morphology and roughness of upskin surfaces in laser powderbed fusion additive manufacturing–Contouring strategy effects. Manufacturing Letters. 2024;41:920–930.
  13. Buhairi MA, Foudzi FM, jamhari FL et al. Review on volumetric energy density: influence on morphology and mechanical properties of Ti6Al4V manufactured via laser powder bed fusion. Progress in Additive Manufacturing. 2023;8(2):265–283.
  14. Avduevskii VS, Koshkin VK (ed.) Fundamentals of heat transfer in aviation and rocket and space technology. Moscow: Mashinostroenie; 1992. 518 p. (In Russ.).
  15. Magrakvelidze TSh. Intensification of heat exchange by artificial roughness-achievements and unresolved problems. Materialy 6-go Minskogo mezhdunarodnogo foruma po Teplomassoobmenu 2008. 16 p. (In Russ.).
  16. Kovalenko LM, Glushkov AF. Heat exchangers with heat transfer intensification. Мoscow: Energoatomizdat; 1986. 240 p. (In Russ.).
  17. Smekalkin AS, Ivanov AV. The effect of surface roughness on the heat transfer coefficient of working fluids in an additive technology boost unit. Vestnik Samarskogo universiteta. Aerokosmicheskaya tekhnika, tekhnologii i mashinostroenie. 2022;21(2):109–114. (In Russ.).
  18. Tsaplin SV, Bolychev SA, Romanov AE. Heat exchange in space. Samara: Samara University; 2018. 92 p. (In Russ.).
  19. Korobov KS, Ripetskii AV, Nikolaev IA et al. Statistical approaches to the analysis of the roughness of vertical surfaces of samples made using SLS technology from AlSi10Mg powder. Problemy mashinostroeniya i nadezhnost' mashin. 2025;54(2):150–158. (In Russ.).
  20. DebRoy T. et al. Additive manufacturing of metallic components–process, structure and properties. Progress in materials science. 2018;(92):112–224.
  21. Rahmati S, Vahabli E. Evaluation of analytical modeling for improvement of surface roughness of FDM test part using measurement results. Int J Adv Manuf Technol. 2015;79:823–829.
  22. Gu D, Shen Y. Balling phenomena in direct laser sintering of stainless steel powder: Metallurgical mechanisms and control methods. Materials & Design. 2009;30(8): 2903–2910.
  23. Niu HJ, Chang ITH. Instability of scan tracks of selective laser sintering of high speed steel powder. Scripta materialia. 1999;41(11):1229–1234.
  24. Masiagutova E, Cabanettes F, Sova A et al. Side surface topography generation during laser powder bed fusion of AlSi 10Mg. Additive Manufacturing. 2021;47.
  25. Yang T, Liu T, Liao W et al. Effect of processing parameters on overhanging surface roughness during laser powder bed fusion of AlSi10Mg. Journal of Manufacturing Processes. 2021;61:440–453.
  26. Saprykina NA. Analysis, modeling, and prediction of surface roughness of copper obtained by selective laser melting. Obrabotka metallov: tekhnologiya, oborudovanie, instrumenty. 2017;(3 (76)). (In Russ.).
  27. Gorbatov IV, Orlov YuA, Antyufeev VA et al. Determination of the geometric accuracy and surface roughness of small round and square cross-section parts obtained depending on the location in the printer's workspace using selective laser melting technology made of 12X18H10T grade steel. Vestnik Kontserna VKO Almaz-Antei. 2019; (1 (28)):59–67. (In Russ.).
  28. Lapteva MA, Belova NA, Raevskikh AN et al. Investigation of the dependence of roughness, surface morphology, and the number of structural defects on laser power, scanning speed, and type of shading in a heatresistant alloy synthesized by the SLS method. Trudy VIAM. 2016;(9 (45)):70–82. (In Russ.).
  29. Subramaniyan AK, Reddy AS, Mathias S et al. Influence of post-processing techniques on the microstructure, properties and surface integrity of AlSi10Mg alloy processed by laser powder bed fusion technique. Surface and Coatings Technology. 2021;425.
  30. Yang T, Liu T, Liao W et al. The influence of process parameters on vertical surface roughness of the AlSi10Mg parts fabricated by selective laser melting. Journal of Materials Processing Technology. 2019;266:26–36. (In Russ.).
  31. Al Islam Sh, Hao L, Javid Z et al. Surface Roughness of Interior Fine Flow Channels in Selective Laser Melted Ti-6Al-4V Alloy Components. Microvachines. 2024;15: 348–371. 

mai.ru — informational site of MAI

Copyright © 2009-2025 by MAI