Fatigue behavior under high frequency loading of materials produced by selective laser melting

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

Based on the enthalpy formulation of a three-dimensional transient nonlinear thermal conductivity problem for a multiphase system, mathematical modeling of the selective laser melting process of titanium and aluminum alloy powders was conducted to produce metallic components. The geometric parameters of a single track, as well as single-layer and multi-layer systems of overlapping tracks, were determined as functions of laser beam power and speed. This enabled the evaluation of the structure and types of defects arising during the layer-by-layer printing of samples. To investigate the influence of single and multiple defects on the fatigue strength of printed samples under high-frequency loading, a previously proposed multi-mode cyclic damage model was used. It was demonstrated that the internal heterogeneity of the microstructure of materials printed using selective laser melting can lead to earlier subsurface initiation of fatigue cracks, significantly reducing fatigue strength and durability. This effect is more pronounced in systems with multiple defects. The proposed models and computational algorithms enable the calculation of the fatigue strength and durability of samples for various defect systems in the microstructure, corresponding to the specified characteristics of the moving laser beam. They also make it possible to identify process parameters for selective laser melting that achieve the best fatigue strength performance under high-frequency loading.

Full Text

Restricted Access

About the authors

I. S. Nikitin

Institute for Computer Aided Design of the RAS

Author for correspondence.
Email: i_nikitin@list.ru
Russian Federation, Moscow

N. G. Burago

Institute for Computer Aided Design of the RAS; Ishlinsky Institute for Problems in Mechanics RAS

Email: i_nikitin@list.ru
Russian Federation, Moscow; Moscow

A. D. Nikitin

Institute for Computer Aided Design of the RAS

Email: i_nikitin@list.ru
Russian Federation, Moscow

B. A. Stratula

Institute for Computer Aided Design of the RAS

Email: i_nikitin@list.ru
Russian Federation, Moscow

References

  1. Dilip J.J.S., Zhang S., Teng C., Zeng K., Robinson C., Pal D., Stucker B. Influence of processing parameters on the evolution of melt pool, porosity, and microstructures in Ti-6Al-4V alloy parts fabricated by selective laser melting // Progress in Additive Manufacturing. 2017. Vol. 2. No 3. Pp. 157–167.
  2. Ali H., Ma L., Ghadbeigi H., Mumtaz K. In-situ residual stress reduction, martensitic decomposition and mechanical properties enhancement through high temperature powder bed pre-heating of Selective Laser Melted Ti6Al4V// Materials Science & Engineering A. 2017. Vol. 695. Pp. 211–220.
  3. Kumar C., Das M., Biswas P. A 3-D Finite Element Analysis of Transient Temperature Profile of Laser Welded Ti-6Al-4V Alloy// Lasers Based Manufacturing, Topics in Mining, Metallurgy and Materials Engineering. S.N. Joshi and U.S. Dixit (Eds.). Springer India. 2015.
  4. Liu H., Yu H., Guo C. et al. Review on Fatigue of Additive Manufactured Metallic Alloys: Microstructure, Performance, Enhancement, and Assessment Methods// Adv. Mater. 2023. 2306570
  5. Babaytsev A.V., Orekhov A.A., Rabinskiy L.N. Properties and microstructure of AlSi10Mg samples obtained by selective laser melting// Nanosci. Techn. 2020. Vol 11. Pp. 213–222.
  6. Babaytsev A., Nikitin A., Ripetskiy A. VHCF of the 3D-Printed Aluminum Alloy AlSi10Mg// Inventions. 2023. Vol. 8. 33.
  7. Nikitin A.D., Stratula B.A. Modeling of cyclic damage and fatigue strength under high-frequency loading of 3D-printed aluminum alloy specimens. Mathematical modeling and numerical methods. 2024. № 1. Pp. 18-37.
  8. Shanyavskiy A.A., Nikitin A.D., Soldatenkov A.P. Very-high cycle fatigue of metals. M.: Fizmatlit. 2022. 496 p.
  9. Nikitin I.S., Burago N.G., Nikitin A.D. Damageability and fatigue failure of structural elements in different modes of cyclic loading// Applied Mathematics and Mechanics. 2022. V. 86. № 2. Pp. 276-290.
  10. Burago N.G., Nikitin I.S., Nikitin A.D., Stratula B.A. Numerical modeling of fatigue failure on the basis of non-local theory of cyclic damageability// Mathematical Modeling. 2024. V. 36. № 3. P. 3–19.
  11. White R.E. An enthalpy formulation of the Stephan problem // SIAM J. Num. Anal. 1982. Vol. 19. № 6. P. 1129—1157.
  12. Samarskiy A.A., Vabishchevich P.N. Computational Heat Transfer. – Moscow: Unitorial Urss. 2009. 782 p.
  13. Gordeev G.A., Krivilev M.D., Ankudinov V.E. Computer modeling of selective laser melting of highly dispersed metal powders // Computational mechanics of continuous media. 2017. V. 10. № 3. P. 293–312.
  14. Knyazeva A.G. Modeling of physical and chemical phenomena in processes of processing of surfaces of materials by high-energy sources// Mathematical modeling of systems and processes. 2009. № 17. P. 66–84.
  15. Agapovichev A.V., Sotov A.V., Smelov V.G. Mathematical modeling of the process of selective laser fusion of titanium alloy powder VT6// Bulletin of Samara University. Aerospace engineering, technology and mechanical engineering. 2020. V. 19. № 2. P. 53–62.
  16. Mirzade F.Kh., Niziev V.G., Panchenko V.Ya. et al. Kinetic approach in numerical modeling of melting and crystallization at laser cladding with powder injection// Physica B: Condensed Matter. 2013. Vol. 423. P. 69–76.
  17. Kovenya V.M., Chirkov D.V. Method of finite differences and finite volumes for solving problems of mathematical physics. Novosibirsk: Pub. NSU, 2013. 86 p.
  18. Schütz W. A history of fatigue // Engineering Fracture Mechanics. 1996. Vol. 54. № 2. P. 263–300. https://doi.org/10.1016/0013-7944(95)00178-6
  19. Bathias C., Paris P. Gigacycle fatigue in mechanical practice. 2004. Dekker. New York. P. 328.
  20. Bathias C., Drouillac L., Le François P. How and why the fatigue S–N curve does not approach a horizontal asymptote // International Journal of Fatigue. 2001. Vol. 23. № 1. P. 143–151.
  21. Smith R.N., Watson P., Topper T.H. A stress-strain parameter for the fatigue of metals // J. of Materials. 1970. Vol. 5. P. 767–78.
  22. Gates N., Fatemi A. Multiaxial variable amplitude fatigue life analysis including notch effects // Int. J. of fatigue. 2016. Vol. 91. Pp. 337–351. https://doi.org/10.1016/j.ijfatigue.2015.12.011
  23. Burago N.G., Nikitin I.S., Nikitin A.D., Stratula B.A. Algorithms for calculation damage processes // Frattura ed Integrità Strutturale. 2019. Vol. 49. P. 212–224.
  24. Jirasek M. Nonlocal models for damage and fracture: comparison of approaches // Int. J. Solids Structures. 1998. Vol. 35. P. 4133–4145.
  25. Bažant Z.P., Jirásek M. Nonlocal integral formulations of plasticity and damage: Survey of progress // J. Eng. Mech. 2002. Vol. 128. P. 1119–1149.
  26. Shutov A.V., Klyuchantsev V.S. Large strain integral-based nonlocal simulation of ductile damage with application to mode-I fracture// International Journal of Plasticity. 2021. Vol. 144. 103061

Supplementary files

Supplementary Files
Action
1. JATS XML
Download
2. Fig. 1. Graphical scheme of the problem of mobile heat flow from the laser beam 1 when it affects the powder layer 2 with the formation of a melt bath 6. The numeral 3 denotes the mobile phase boundary, 4 - substrate of material in solid phase, 5 - cooled laser trace in the form of material in solid phase.

Download (106KB)
Indexing metadata
3. Fig. 2. Single SLP track in titanium alloy, q0 = 100 W, v = 800 mm/s, top view - a), cross-sectional view of the track and its fusion with the substrate - b), where w is the track width, d is the depth.

Download (148KB)
Indexing metadata
4. Fig. 3. Results of calculations of track width w - a) and depth d - b) at different laser beam velocities v (mm/s) taking into account evaporation from the surface of the melt bath. Experimental data “1” from [1] are compared with the calculation results “2”.

Download (170KB)
Indexing metadata
5. Fig. 4. Structure of the printed aluminum alloy observed in the electron microscope, (a) - top view, q0 = 370 W, v = 650 mm/s, electron microscope, (b) - cross-section of the near-surface layer, q0 = 370 W, v = 450 mm/s, optical microscope.

Download (341KB)
Indexing metadata
6. Fig. 5. Overmelt zones (blue - 0 transitions, yellow - 3 transitions, orange - 4 transitions) for three-layer printing - (a), four-layer printing - (b).

Download (260KB)
Indexing metadata
7. Fig. 6. Geometrical structure of overlapping tracks. Upper part - calculation, lower part - experiment, optical microscope.

Download (149KB)
Indexing metadata
8. Figure 7. Defect structure results for titanium alloy, (a) - q0 = 50 W, v = 1000 mm/s, under-melting, (b) - q0 = 50 W, v = 500 mm/s, multiple remelts, no under-melts.

Download (259KB)
Indexing metadata
9. Figure 8. Specimen with sharp notch without rounding - (a), meshes with characteristic cell size in the vicinity of the notch apex of 0.1 mm - (b), with 0.05 mm - (c).

Download (459KB)
Indexing metadata
10. Fig. 9. Examples of calculation of quasi-cracks nucleation and development. Nucleation of a quasi-crack - (a), its development to a length of 1 mm - (b), its development to a length of 2 mm - (c).

Download (58KB)
Indexing metadata
11. Figure 10. Number of cycles N before the nucleation of a crack from a sharp notch. Number of cycles as a function of mesh size h - a), normalized number of cycles - b). Curve 1 - without averaging procedure, curve 2 - with averaging.

Download (260KB)
Indexing metadata
12. Figure 11. Defect systems in the specimen. Stress concentration on a linear defect system - a), stress concentration on a bilayer defect system - b).

Download (70KB)
Indexing metadata
13. Fig. 12. Nucleation and development of a quasi-crack on a two-layer defect system. Nucleation, N =1.31E+09 - a), development, N =1.33E+09 - b).

Download (38KB)
Indexing metadata

Copyright (c) 2024 Russian Academy of Sciences