Tailoring heat treatments for Laser Powder Bed Fusion (LPBF) processed materials is critical to ensure superior and repeatable material properties for high-end applications. This tailoring requires in-depth understanding of the LPBF-processed material. Therefore, the current study aims at unravelling the threefold interrelationship between the process (LPBF and heat treatment), the microstructure at different scales (macro-, meso-, micro-, and nano-scale), and the macroscopic material properties of AlSi10Mg. A similar solidification trajectory applies at different length scales when comparing the solidification of AlSi10Mg, ranging from mould-casting to rapid solidification (LPBF). The similarity in solidification trajectories triggers the reason why the Brody-Flemings cellular microsegregation solidification model could predict the cellular morphology of the LPBF as-printed microstructure. Where rapid solidification occurs at a much finer scale, the LPBF microstructure exhibits a significant grain refinement and a high degree of silicon (Si) supersaturation. This study has identified the grain refinement and Si supersaturation as critical assets of the as-printed microstructure, playing a vital role in achieving superior mechanical and thermal properties during heat treatment. Next, an electrical conductivity model could accurately predict the Si solute concentration in LPBF-processed and heat-treated AlSi10Mg and allows understanding the microstructural evolution during heat treatment. The LPBF-processed and heat-treated AlSi10Mg conditions (as-built (AB), direct-aged (DA), stress-relieved (SR), preheated (PH)) show an interesting range of superior mechanical properties (tensile strength: 300-450 MPa, elongation: 4-13%) compared to the mould-cast T6 reference condition.

D Systems Leuven Grauwmeer 14 3001 Leuven Belgium

Department for Nanostructures Materials Jozef Stefan Institute Jamova c 39 1000 Ljubljana Slovenia

Department of Materials Engineering KU Leuven Kasteelpark Arenberg 44 3001 Leuven Belgium

Department of Mechanical Engineering KU Leuven Celestijnenlaan 300 3001 Leuven Belgium

Department of Physics Electron Microscopy for Materials Science University of Antwerp Groenenborgerlaan 171 2020 Antwerp Belgium

Institute of Thermomechanics Academy of Sciences of the Czech Republic Dolejškova 5 182000 Prague Czech Republic

Zobrazit více v PubMed

DebRoy T, et al. Additive manufacturing of metallic components—Process, structure and properties. Prog. Mater. Sci. 2018;92:112–224. doi: 10.1016/j.pmatsci.2017.10.001. DOI

Li N, et al. Progress in additive manufacturing on new materials: A review. J. Mater. Sci. Technol. 2018 doi: 10.1016/j.jmst.2018.09.002. DOI

de Formanoir C, et al. Increasing the productivity of laser powder bed fusion: Influence of the hull-bulk strategy on part quality, microstructure and mechanical performance of Ti-6Al-4V. Addit. Manuf. 2020;33:101129.

Metelkova J, Ordnung D, Kinds Y, Witvrouw A, van Hooreweder B. Improving the quality of up-facing inclined surfaces in laser powder bed fusion of metals using a dual laser setup. Procedia CIRP. 2020;94:266–269. doi: 10.1016/j.procir.2020.09.050. DOI

Aversa A, et al. Aluminum alloys specifically designed for new aluminum alloys specifically designed for laser powder bed fusion: A review laser powder bed fusion: a review abstract. Materials. 2019 doi: 10.3390/ma12071007. PubMed DOI PMC

Li W, et al. Effect of heat treatment on AlSi10Mg alloy fabricated by selective laser melting: Microstructure evolution, mechanical properties and fracture mechanism. Mater. Sci. Eng. A. 2016;663:116–125. doi: 10.1016/j.msea.2016.03.088. DOI

Takata N, Kodaira H, Sekizawa K, Suzuki A, Kobashi M. Change in microstructure of selectively laser melted AlSi10Mg alloy with heat treatments. Mater. Sci. Eng. A. 2017;704:218–228. doi: 10.1016/j.msea.2017.08.029. DOI

Buchbinder D, et al. Selective laser melting of aluminum die-cast alloy—Correlations between process parameters, solidification conditions, and resulting mechanical properties. J. Laser. Appl. 2015;27:S29205. doi: 10.2351/1.4906389. DOI

Aboulkhair NT, Maskery I, Tuck C, Ashcroft I, Everitt NM. The microstructure and mechanical properties of selectively laser melted AlSi10Mg: The effect of a conventional T6-like heat treatment. Mater. Sci. Eng. A. 2016;667:139–146. doi: 10.1016/j.msea.2016.04.092. DOI

Fiocchi J, Tuissi A, Bassani P, Biffi CA. Low temperature annealing dedicated to AlSi10Mg selective laser melting products. J. Alloys Compd. 2017;695:3402–3409. doi: 10.1016/j.jallcom.2016.12.019. DOI

Van Cauwenbergh, P., Beckers, A., Lore, T., Van Hooreweder, B. & Vanmeensel, K. Heat treatment optimization via thermo-physical characterization of AlSi7Mg and AlSi10Mg manufactured by laser powder bed fusion.

DebRoy T, et al. Scientific, technological and economic issues in metal printing and their solutions. Nat. Mater. 2019 doi: 10.1038/s41563-019-0408-2. PubMed DOI

Collins PC, Brice DA, Samimi P, Ghamarian I, Fraser HL. Microstructural control of additively manufactured metallic materials. Annu. Rev. Mater. Res. 2016;46:63–91. doi: 10.1146/annurev-matsci-070115-031816. DOI

Ivekovic, A., Montero-Sistiaga, M. L., Vleugels, J., Kruth, J.-P. & Vanmeensel, K. Combined experimental numerical investigation of crack mitigation in SLM processed Ni-based superalloys (submitted for revision).

Sedlak, P. & Seiner, H. J. Z. Determination of All 21 Independent Elastic Coefficients of Generally Anisotropic Solids by Resonant Ultrasound Spectroscopy : Benchmark Examples. 1073–1085 (2014). 10.1007/s11340-014-9862-6

Seiner H, et al. Application of ultrasonic methods to determine elastic anisotropy of polycrystalline copper processed by equal-channel angular pressing. Acta Mater. 2010;58:235–247. doi: 10.1016/j.actamat.2009.08.071. DOI

Jones W, March NH. Theoretical solid state physics. Wiley; 1973.

Bergman TL, Lavine AS, Incropera FP. Fundamentals of Heat and Mass Transfer. 7. Wiley; 2011.

Glicksman ME. Principles of Solidification. Springer; 2011.

Kou S. Welding Metallurgy. Wiley; 2002.

Mohammadpour P, Plotkowski A, Phillion AB. Revisiting solidi fi cation microstructure selection maps in the frame of additive manufacturing. Addit. Manuf. 2020;31:100936.

Kurz W. Solidification microstructure-processing maps: Theory and application. Adv. Eng. Mater. 2001;3:443–452. doi: 10.1002/1527-2648(200107)3:7<443::AID-ADEM443>3.0.CO;2-W. DOI

Hu H, Ding X, Wang L. Numerical analysis of heat transfer during multi-layer selective laser melting of AlSi10Mg. Optik. 2016;127:8883–8891. doi: 10.1016/j.ijleo.2016.06.115. DOI

Li Y, Gu D. Parametric analysis of thermal behavior during selective laser melting additive manufacturing of aluminum alloy powder. Mater. Des. 2014;63:856–867. doi: 10.1016/j.matdes.2014.07.006. DOI

Matyja H. The effect of cooling rate on the dendrite spacing in splat-cooled aluminium alloys. J. Inst. Met. 1968;96:30–32.

Tang, M. Inclusions , Porosity, and Fatigue of AlSi10Mg Parts Produced by Selective Laser Melting (2017).

Kurz, W. & Fisher, D. J.

Gu D, Shi Q, Lin K, Xi L. Microstructure and performance evolution and underlying thermal mechanisms of Ni-based parts fabricated by selective laser melting. Addit. Manuf. 2018;22:265–278.

Pierantoni M, Gremaud M, Magning P, Stoll D, Kurz W. The coupled zone of rapidly solidified Al-Si alloys in laser treatment. Acta Mater. 1992;40:1637–1644. doi: 10.1016/0956-7151(92)90106-O. DOI

Maeshima T, Oh-ishi K. Solute clustering and supersaturated solid solution of AlSi10Mg alloy fabricated by selective laser melting. Heliyon. 2019;5:e01186. doi: 10.1016/j.heliyon.2019.e01186. PubMed DOI PMC

Shin YH, Kim MS, Oh KS, Yoon EP, Hong CP. An analytical model of microsegregation in alloy solidification. ISIJ Int. 2001;41:158–163. doi: 10.2355/isijinternational.41.158. DOI

Won YM, Thomas BG. Simple model of microsegregation during solidification of steels. Metall. Mater. Trans. A Phys. Metall. Mater. Sci. 2001;32:1755–1767. doi: 10.1007/s11661-001-0152-4. DOI

Flemings MC. Solidification Processing. McGraw-Hill; 1974.

Zhao L, et al. Damage mechanisms in selective laser melted AlSi10Mg under as built and different post-treatment conditions. Mater. Sci. Eng. A. 2019;764:138210. doi: 10.1016/j.msea.2019.138210. DOI

Li XP, et al. A selective laser melting and solution heat treatment refined Al–12Si alloy with a controllable ultrafine eutectic microstructure and 25 % tensile ductility. Acta Mater. 2015;95:74–82. doi: 10.1016/j.actamat.2015.05.017. DOI

Sobolev SL. Direct Driving force for binary alloy solidification under far from local equilibrium conditions. Acta Mater. 2015;93:256–263. doi: 10.1016/j.actamat.2015.04.028. DOI

Tang M, Pistorius PC, Narra S, Beuth JL. Rapid solidification : Selective laser melting of AlSi10Mg. Jom. 2016;68:960–966. doi: 10.1007/s11837-015-1763-3. DOI

Marola S, et al. A comparison of selective laser melting with bulk rapid solidification of AlSi10Mg alloy. J. Alloys Compd. 2018;742:271–279. doi: 10.1016/j.jallcom.2018.01.309. DOI

Hatch, J. E. Aluminum: properties and physical metallurgy. In

Mulazimoglu MH, Drew RAL, Gruzleski JE. Solution treatment study of cast Al–Si alloys by electrical conductivity. Can. Metall. Q. 1989;28:251–258. doi: 10.1179/cmq.1989.28.3.251. DOI

Mulazimoglu MH, Drew RAL, Gruzleski JE. The electrical conductivity of cast Al−Si alloys in the range 2 to 12.6 wt pct silicon. Metall. Trans. A. 1989;20:383–389. doi: 10.1007/BF02653917. DOI

Wei P, et al. The AlSi10Mg samples produced by selective laser melting: Single track, densification, microstructure and mechanical behavior. Appl. Surf. Sci. 2017;408:38–50. doi: 10.1016/j.apsusc.2017.02.215. DOI

Chen B, et al. Strength and strain hardening of a selective laser melted AlSi10Mg alloy. Scr. Mater. 2017;141:45–49. doi: 10.1016/j.scriptamat.2017.07.025. DOI

Kim DK, et al. Evaluation of the stress-strain relationship of constituent phases in AlSi10Mg alloy produced by selective laser melting using crystal plasticity FEM. J. Alloys Compd. 2017;714:687–697. doi: 10.1016/j.jallcom.2017.04.264. DOI

Newnham R. Properties of Materials—Anisotropy, Symmetry, Structure. Oxford University Press; 2005.

Zhang J, Song B, Wei Q, Bourell D, Shi Y. A review of selective laser melting of aluminum alloys: Processing, microstructure, property and developing trends. J. Mater. Sci. Technol. 2018 doi: 10.1016/j.jmst.2018.09.004. DOI

Suryawanshi J, et al. Simultaneous enhancements of strength and toughness in an Al-12Si alloy synthesized using selective laser melting. Acta Mater. 2016;115:285–294. doi: 10.1016/j.actamat.2016.06.009. DOI

Yang KV, Rometsch P, Davies CH, Huang A, Wu X. Effect of heat treatment on the microstructure and anisotropy in mechanical properties of A357 alloy produced by selective laser melting. Mater. Des. 2018;154:275–290. doi: 10.1016/j.matdes.2018.05.026. DOI

Rashid R, et al. Effect of energy per layer on the anisotropy of selective laser melted AlSi12 aluminium alloy. Addit. Manuf. 2018;22:426–439.

Kempen K, Thijs L, Humbeeck JV, Kruth J. Mechanical properties of AlSi10Mg produced by Selective Laser Melting. Phys. Procedia. 2012;39:439–446. doi: 10.1016/j.phpro.2012.10.059. DOI

Utilizing PBF-LB/M AlSI10Mg alloy post-processed via KOBO-extrusion and subsequent cold drawing to obtain high-strength wire

Case Study of Additively Manufactured Mountain Bike Stem