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3D printing of high-strength aluminium alloys

Nature volume 549, pages 365–369 (2017)Cite this article

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Abstract

Metal-based additive manufacturing, or three-dimensional (3D) printing, is a potentially disruptive technology across multiple industries, including the aerospace, biomedical and automotive industries. Building up metal components layer by layer increases design freedom and manufacturing flexibility, thereby enabling complex geometries, increased product customization and shorter time to market, while eliminating traditional economy-of-scale constraints. However, currently only a few alloys, the most relevant being AlSi10Mg, TiAl6V4, CoCr and Inconel 718, can be reliably printed1,2; the vast majority of the more than 5,500 alloys in use today cannot be additively manufactured because the melting and solidification dynamics during the printing process lead to intolerable microstructures with large columnar grains and periodic cracks3,4,5. Here we demonstrate that these issues can be resolved by introducing nanoparticles of nucleants that control solidification during additive manufacturing. We selected the nucleants on the basis of crystallographic information and assembled them onto 7075 and 6061 series aluminium alloy powders. After functionalization with the nucleants, we found that these high-strength aluminium alloys, which were previously incompatible with additive manufacturing, could be processed successfully using selective laser melting. Crack-free, equiaxed (that is, with grains roughly equal in length, width and height), fine-grained microstructures were achieved, resulting in material strengths comparable to that of wrought material. Our approach to metal-based additive manufacturing is applicable to a wide range of alloys and can be implemented using a range of additive machines. It thus provides a foundation for broad industrial applicability, including where electron-beam melting or directed-energy-deposition techniques are used instead of selective laser melting, and will enable additive manufacturing of other alloy systems, such as non-weldable nickel superalloys and intermetallics. Furthermore, this technology could be used in conventional processing such as in joining, casting and injection moulding, in which solidification cracking and hot tearing are also common issues.

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Figure 1: Additive manufacturing of metal alloys via selective laser melting.
Figure 2: Nanoparticle assembly on additive metal feedstock.
Figure 3: Solidification behaviour of additive aluminium alloys.
Figure 4: Mechanical testing of 3D-printed aluminium alloys.

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References

  1. Lewandowski, J. J. & Seifi, M. Metal additive manufacturing: a review of mechanical properties. Annu. Rev. Mater. Res. 46, 151–186 (2016)

    Article  CAS  ADS  Google Scholar 

  2. Frazier, W. E. Metal additive manufacturing: a review. J. Mater. Eng. Perform. 23, 1917–1928 (2014)

    Article  CAS  Google Scholar 

  3. Collins, F. R. & Dudas, J. H. Preventing weld cracks in high-strength aluminum alloys. Weld. J. 45, 241 (1966)

    Google Scholar 

  4. Kaufmann, N. et al. Influence of process parameters on the quality of aluminium alloy EN AW 7075 using selective laser melting (SLM). Phys. Procedia 83, 918–926 (2016)

    Article  CAS  ADS  Google Scholar 

  5. Zhang, H., Zhu, H., Qi, T., Hu, Z. & Zeng, X. Selective laser melting of high strength Al-Cu-Mg alloys: processing, microstructure and mechanical properties. Mater. Sci. Eng. A 656, 47–54 (2016)

    Article  CAS  Google Scholar 

  6. Kurz, W . & Fisher, D. J. Fundamentals of Solidification (Trans Tech Publications, 1998)

  7. Coniglio, N. & Cross, C. E. Initiation and growth mechanisms for weld solidification cracking. Int. Mater. Rev. 58, 375–397 (2013)

    Article  CAS  Google Scholar 

  8. Rappaz, M., Drezet, J. & Gremaud, M. A new hot-tearing criterion. Metall. Mater. Trans. A 30, 449–455 (1999)

    Article  Google Scholar 

  9. Yuan, L., O’Sullivan, C. & Gourlay, C. M. Exploring dendrite coherency with the discrete element method. Acta Mater. 60, 1334–1345 (2012)

    Article  CAS  Google Scholar 

  10. Collins, P. C., Brice, D. A., Samimi, P., Ghamarian, I. & Fraser, H. L. Microstructural control of additively manufactured metallic materials. Annu. Rev. Mater. Res. 46, 63–91 (2016)

    Article  CAS  ADS  Google Scholar 

  11. Easton, M. A. & Stjohn, D. Grain refinement of aluminum alloys : part I. The nucleant and solute paradigms — a review of the literature. Metall. Mater. Trans. A 30, 1613–1623 (1999)

    Article  Google Scholar 

  12. Ding, Y. et al. Microstructure and mechanical property considerations in additive manufacturing of aluminum alloys. MRS Bull. 41, 745–751 (2016)

    Article  CAS  Google Scholar 

  13. Schmidtke, K., Palm, F., Hawkins, A. & Emmelmann, C. Process and mechanical properties: applicability of a scandium modified Al-alloy for laser additive manufacturing. Phys. Procedia 12, 369–374 (2011)

    Article  CAS  ADS  Google Scholar 

  14. Material Data Sheet — Scalmalloy (APWorks, 2016)

  15. Starke, E. A. & Staley, J. T. Application of modern aluminum alloys to aircraft. Prog. Aerosp. Sci. 32, 131–172 (1996)

    Article  Google Scholar 

  16. Immarigeon, J. P. et al. Lightweight materials for aircraft applications. Mater. Charact. 35, 41–67 (1995)

    Article  CAS  Google Scholar 

  17. Miller, W. et al. Recent development in aluminium alloys for the automotive industry. Mater. Sci. Eng. A 280, 37–49 (2000)

    Article  Google Scholar 

  18. Society of Automotive Engineers & American Society for Testing and Materials. Metals and Alloys in the Unified Numbering System (ASTM International, 2012)

  19. Nelson, W. Duralumin Welding. Report No. 399 (National Advisory Committee for Aeronautics, 1927)

  20. Pumphrey, W. I. & Lyons, J. V. Cracking during the casting and welding of the more common binary aluminum alloys. J. Inst. Met. 74, 439–455 (1948)

    CAS  Google Scholar 

  21. Gourlay, C. M. & Dahle, A. K. Dilatant shear bands in solidifying metals. Nature 445, 70–73 (2007)

    Article  CAS  ADS  Google Scholar 

  22. Murray, J., Peruzzi, A. & Abriata, J. P. The Al-Zr (aluminum-zirconium) system. J. Phase Equilibria 13, 277–291 (1992)

    Article  CAS  Google Scholar 

  23. Murty, B. S., Kori, S. A. & Chakraborty, M. Grain refinement of aluminium and its alloys by heterogeneous nucleation and alloying. Int. Mater. Rev. 47, 3–29 (2002)

    Article  CAS  Google Scholar 

  24. Dehoff, R. R. et al. Site specific control of crystallographic grain orientation through electron beam additive manufacturing. Mater. Sci. Technol. 31, 931–938 (2015)

    Article  CAS  Google Scholar 

  25. Martorano, M. A., Beckermann, C. & Gandin, C.-A. A solutal interaction mechanism for the columnar-to-equiaxed transition in alloy solidification. Metall. Mater. Trans. A 34, 1657–1674 (2003)

    Article  Google Scholar 

  26. Hunt, J. D. Steady state columnar and equiaxed growth of dendrites and eutectic. Mater. Sci. Eng. 65, 75–83 (1984)

    Article  CAS  ADS  Google Scholar 

  27. Eskin, D. G., Suyitno & Katgerman, L. Mechanical properties in the semi-solid state and hot tearing of aluminium alloys. Prog. Mater. Sci. 49, 629–711 (2004)

    Article  CAS  Google Scholar 

  28. TCAL4: TCS Al-based Alloy Databasehttp://www.thermocalc.com/media/19881/tcal4.pdf (Thermo-Calc, 2016)

  29. Aziz, M. J. Model for solute redistribution during rapid solidification. J. Appl. Phys. 53, 1158–1168 (1982)

    Article  CAS  ADS  Google Scholar 

  30. Yu, C. Y., Kao, P. W. & Chang, C. P. Transition of tensile deformation behaviors in ultrafine-grained aluminum. Acta Mater. 53, 4019–4028 (2005)

    Article  CAS  Google Scholar 

  31. CL 30AL/CL 31AL Aluminium Alloy (Concept Laser, Hofmann Innovation Group, 2012)

  32. Boyer, H. E. & Gail, T. L. Materials Handbook Desk Edition (American Society for Metals, 1985)

Download references

Acknowledgements

We acknowledge financial support by HRL Laboratories, LLC, and thank D. Martin for her artistic contribution to the figures, as well as B. Carter of HRL Laboratories, LLC, X. Li of the University of California, Los Angeles, and K. Hemker of John Hopkins University for discussions.

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Authors and Affiliations

  1. Architected Materials Department, HRL Laboratories LLC, Sensors and Materials Laboratory, Malibu, California, USA

    John H. Martin, Brennan D. Yahata, Jacob M. Hundley, Justin A. Mayer & Tobias A. Schaedler

  2. Materials Department, University of California, Santa Barbara, California, USA

    John H. Martin & Tresa M. Pollock

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Contributions

J.H.M., B.D.Y., J.M.H., T.A.S. and T.M.P. analysed the results and wrote the manuscript. J.H.M., B.D.Y. and T.A.S. designed the experiments. B.D.Y. and J.A.M. functionalized the feedstock material and operated the Concept Laser M2. J.H.M., B.D.Y. and J.A.M. prepared the metallurgical specimens and performed the optical and electron microscopy and the mechanical testing.

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Correspondence to John H. Martin.

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The authors declare no competing financial interests.

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Reviewer Information Nature thanks P. Collins, I. Todd and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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Extended data figures and tables

Extended Data Figure 1 SEM image of aluminium alloy 7075 powder.

Extended Data Figure 2 As-printed Al7075 parts for tensile testing and microstructure evaluation.

a, Stock Al7075. b, Al7075 + Zr.

Extended Data Figure 3 Ageing behaviour of additive Al7075.

Extended Data Figure 4 Stress–strain curves for the materials tested in this study, indicating high repeatability in the Al7075 + Zr material.

The colour indicates the material type, with curves of the same colour indicating replicate samples.

Extended Data Figure 5 Scheil solidification curves for aluminium alloys AlSi10Mg, Al7075 and Al6061.

The curve for Al6061 is from ref. 28.

Extended Data Figure 6 Micrographs of etched Al6061, processed as received.

Large cracks are observed in the absence of Zr (left). With the addition of Zr nanoparticles, no cracking is observed, but there is some residual porosity (right). Rows indicate increasing magnification.

Extended Data Figure 7 Micrographs of etched Al7075, processed as received.

Large networks of cracks are observed in the absence of Zr (left). With the addition of Zr nanoparticles, no cracking is observed, but there is some residual porosity (right). Rows indicate increasing magnification.

Extended Data Figure 8 EBSD inverse pole figure of 3D-printed stock 7075 indicating large networks of columnar cracking.

Build direction is vertical to the page.

Extended Data Table 1 Specifications of the Concept Laser M2 selective laser melting system
Full size table

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Martin, J., Yahata, B., Hundley, J. et al. 3D printing of high-strength aluminium alloys. Nature 549, 365–369 (2017). https://doi.org/10.1038/nature23894

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