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Ultrastrong steel via minimal lattice misfit and high-density nanoprecipitation

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Next-generation high-performance structural materials are required for lightweight design strategies and advanced energy applications. Maraging steels, combining a martensite matrix with nanoprecipitates, are a class of high-strength materials with the potential for matching these demands1,2,3. Their outstanding strength originates from semi-coherent precipitates4,5, which unavoidably exhibit a heterogeneous distribution that creates large coherency strains, which in turn may promote crack initiation under load6,7,8. Here we report a counterintuitive strategy for the design of ultrastrong steel alloys by high-density nanoprecipitation with minimal lattice misfit. We found that these highly dispersed, fully coherent precipitates (that is, the crystal lattice of the precipitates is almost the same as that of the surrounding matrix), showing very low lattice misfit with the matrix and high anti-phase boundary energy, strengthen alloys without sacrificing ductility. Such low lattice misfit (0.03 ± 0.04 per cent) decreases the nucleation barrier for precipitation, thus enabling and stabilizing nanoprecipitates with an extremely high number density (more than 1024 per cubic metre) and small size (about 2.7 ± 0.2 nanometres). The minimized elastic misfit strain around the particles does not contribute much to the dislocation interaction, which is typically needed for strength increase. Instead, our strengthening mechanism exploits the chemical ordering effect that creates backstresses (the forces opposing deformation) when precipitates are cut by dislocations. We create a class of steels, strengthened by Ni(Al,Fe) precipitates, with a strength of up to 2.2 gigapascals and good ductility (about 8.2 per cent). The chemical composition of the precipitates enables a substantial reduction in cost compared to conventional maraging steels owing to the replacement of the essential but high-cost alloying elements cobalt and titanium with inexpensive and lightweight aluminium. Strengthening of this class of steel alloy is based on minimal lattice misfit to achieve maximal precipitate dispersion and high cutting stress (the stress required for dislocations to cut through coherent precipitates and thus produce plastic deformation), and we envisage that this lattice misfit design concept may be applied to many other metallic alloys.

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Figure 1: Mechanical properties and typical STEM images of the solution-annealed (15 min at 950 °C) and of the aged (3 h at 500 °C) Ni(Al,Fe)-maraging steels.
Figure 2: High-resolution HAADF STEM images and three-dimensional reconstruction of an APT dataset confirming the B2 nature of the precipitates with full lattice coherence.
Figure 3: Atom probe analysis showing tomography and composition of the precipitates.
Figure 4: Synchrotron XRD results showing the overall phase transformation and extremely low lattice misfit between bcc matrix and B2 precipitates.

Change history

  • 27 April 2017

    The y-axis units were corrected in Fig. 1a; an additional statement was included in the Acknowledgements.


  1. Decker, R. F. & Floreen, S. in Maraging Steels: Recent Developments and Applications (ed. Wilson, R. K. ) 1–38 (TMS-AIME, 1988)

  2. Floreen, S. The physical metallurgy of maraging steels. Metall. Rev. 13, 115–128 (1968)

    CAS  Google Scholar 

  3. Raabe, D., Ponge, D., Dmitrieva, O. & Sander, B. Nanoprecipitate-hardened 1.5GPa steels with unexpected high ductility. Scr. Mater. 60, 1141–1144 (2009)

    CAS  Article  Google Scholar 

  4. Tewari, R. et al. Precipitation in 18 wt% Ni maraging steel of grade 350. Acta Mater. 48, 1187–1200 (2000)

    CAS  Article  Google Scholar 

  5. Sha, W. & Guo, Z. Maraging Steels: Modelling of Microstructure, Properties and Applications 1st edn, 63 (Woodhead, 2009)

  6. Ashby, M. F. Work hardening of dispersion-hardened crystals. Phil. Mag. 14, 1157–1178 (1966)

    ADS  CAS  Article  Google Scholar 

  7. Ooi, S. W., Hill, P., Rawson, M. & Bhadeshia, H. D. Effect of retained austenite and high temperature Laves phase on the work hardening of an experimental maraging steel. Mater. Sci. Eng. A 564, 485–492 (2013)

    CAS  Article  Google Scholar 

  8. Viswanathan, U. K., Dey, G. K. & Asundi, M. K. Precipitation hardening in 350 grade maraging steel. Metall. Trans. A 24, 2429–2442 (1993)

    Article  Google Scholar 

  9. Ritchie, R. O. The conflicts between strength and toughness. Nat. Mater. 10, 817–822 (2011)

    ADS  CAS  Article  Google Scholar 

  10. Lu, K., Lu, L. & Suresh, S. Strengthening materials by engineering coherent internal boundaries at the nanoscale. Science 324, 349–352 (2009)

    ADS  CAS  Article  Google Scholar 

  11. Li, Z. M. et al. Metastable high-entropy dual-phase alloys overcome the strength–ductility trade-off. Nature 534, 227–230 (2016)

    ADS  CAS  Article  Google Scholar 

  12. Gault, B. et al. Advances in the calibration of atom probe tomographic reconstruction. J. Appl. Phys. 105, 034913 (2009)

    ADS  Article  Google Scholar 

  13. Moody, M. P. et al. Qualification of the tomographic reconstruction in atom probe by advanced spatial distribution map techniques. Ultramicroscopy 109, 815–824 (2009)

    CAS  Article  Google Scholar 

  14. Gault, B. et al. Atom probe tomography investigation of Mg site occupancy within δ′ precipitates in an Al–Mg–Li alloy. Scr. Mater. 66, 903–906 (2012)

    CAS  Article  Google Scholar 

  15. Kapoor, M. et al. Aging characteristics and mechanical properties of 1600 MPa body-centered cubic Cu and B2-NiAl precipitation-strengthened ferritic steel. Acta Mater. 73, 56–74 (2014)

    CAS  Article  Google Scholar 

  16. Jiao, Z. B. et al. Precipitation mechanism and mechanical properties of an ultra-high strength steel hardened by nanoscale NiAl and Cu particles. Acta Mater. 97, 58–67 (2015)

    CAS  Article  Google Scholar 

  17. Guo, Z., Sha, W. & Vaumousse, D. Microstructural evolution in a PH13–8 stainless steel after ageing. Acta Mater. 51, 101–116 (2003)

    CAS  Article  Google Scholar 

  18. Ping, D. H. et al. Microstructural evolution in 13Cr–8Ni–2.5Mo–2Al martensitic precipitation-hardened stainless steel. Mater. Sci. Eng. A 394, 285–295 (2005)

    Article  Google Scholar 

  19. Blavette, D., Cadel, E., Fraczkiewicz, A. & Menand, A. Three-dimensional atomic-scale imaging of impurity segregation to line defects. Science 286, 2317–2319 (1999)

    CAS  Article  Google Scholar 

  20. Smith, G. D. W., Hudson, D., Styman, P. D. & Williams, C. A. Studies of dislocations by field ion microscopy and atom probe tomography. Phil. Mag. 93, 3726–3740 (2013)

    ADS  CAS  Article  Google Scholar 

  21. Kuzmina, M. et al. Linear complexions: confined chemical and structural states at dislocations. Science 349, 1080–1083 (2015)

    ADS  CAS  Article  Google Scholar 

  22. Hellman, O. C. et al. Analysis of three-dimensional atom-probe data by the proximity histogram. Microsc. Microanal. 6, 437–444 (2000)

    ADS  CAS  Article  Google Scholar 

  23. Williamson, G. K. & Hall, W. H. X-ray line broadening from filed aluminium and wolfram. Acta Metall. 1, 22–31 (1953)

    CAS  Article  Google Scholar 

  24. Ungár, T. & Borbély, A. The effect of dislocation contrast on x-ray line broadening: a new approach to line profile analysis. Appl. Phys. Lett. 69, 3173–3175 (1996)

    ADS  Article  Google Scholar 

  25. Teng, Z. K. et al. Neutron-diffraction study and modeling of the lattice parameters of a NiAl-precipitate-strengthened Fe-based alloy. Acta Mater. 60, 5362–5369 (2012)

    CAS  Article  Google Scholar 

  26. Sonderegger, B. & Kozeschnik, E. Generalized nearest-neighbor broken-bond analysis of randomly oriented coherent interfaces in multicomponent fcc and bcc structures. Metall. Mater. Trans. A 40, 499–510 (2009)

    Article  Google Scholar 

  27. Lu, K. Stabilizing nanostructures in metals using grain and twin boundary architectures. Nat. Rev. Mater . 1, 16019 (2016)

    ADS  CAS  Article  Google Scholar 

  28. Sha, W., Cerezo, A. & Smith, G. D. W. Phase chemistry and precipitation reactions in maraging steels. Part III. Model alloys. Metall. Trans. A 24, 1241–1249 (1993)

    Article  Google Scholar 

  29. Kim, Y. G., Kim, G. S., Lee, C. S. & Lee, D. N. Microstructure and mechanical properties of a cobalt-free tungsten-bearing maraging steel. Mater. Sci. Eng. 79, 133–140 (1986)

    CAS  Article  Google Scholar 

  30. Pereloma, E. & Edmonds, D. V. Phase Transformations in Steels: Diffusionless Transformations, High strength steels, Modelling and Advanced Analytical Techniques 1st edn, 335 (Woodhead, 2012)

  31. Thompson, K. et al. In situ site-specific specimen preparation for atom probe tomography. Ultramicroscopy 107, 131–139 (2007)

    CAS  Article  Google Scholar 

  32. Gault, B. et al. Advances in the reconstruction of atom probe tomography data. Ultramicroscopy 111, 448–457 (2011)

    CAS  Article  Google Scholar 

  33. Kingham, D. R. The post-ionization of field evaporated ions: a theoretical explanation of multiple charge states. Surf. Sci. 116, 273–301 (1982)

    ADS  CAS  Article  Google Scholar 

  34. Nelson, J. B. & Riley, D. P. An experimental investigation of extrapolation methods in the derivation of accurate unit-cell dimensions of crystals. Proc. Phys. Soc. 57, 160–177 (1945)

    ADS  CAS  Article  Google Scholar 

  35. Nitta, H. et al. Diffusion of molybdenum in α-iron. Acta Mater. 50, 4117–4125 (2002)

    CAS  Article  Google Scholar 

  36. Hettich, G., Mehrer, H. & Maier, K. Self-diffusion in ferromagnetic α-iron. Scr. Metall. 11, 795–802 (1977)

    CAS  Article  Google Scholar 

  37. Bergner, D. & Khaddour, Y. Impurity and chemical diffusion of Al in bcc and fcc iron. Defect Diffus. Forum. 95, 709–714 (1993)

    Article  Google Scholar 

  38. Gale, W. F. & Totemeier, T. C. Smithells Metals Reference Book 8th edn, 13–60 (Butterworth-Heinemann, 2003)

  39. Kelly, P. Progress report on recent advances in physical metallurgy: (C) The quantitative relationship between microstructure and properties in two-phase alloys. Int. Metall. Rev. 18, 31–36 (1973)

    Article  Google Scholar 

  40. Baker, I. A review of the mechanical properties of B2 compounds. Mater. Sci. Eng. A 192–193, 1–13 (1995)

    Article  Google Scholar 

  41. Gladman, T. Precipitation hardening in metals. Mater. Sci. Technol. 15, 30–36 (1999)

    CAS  Article  Google Scholar 

  42. Noebe, R. D., Bowman, R. R. & Nathal, M. V. Physical and mechanical properties of the B2 compound NiAl. Int. Mater. Rev. 38, 193–232 (1993)

    CAS  Article  Google Scholar 

  43. Jiao, Z. B. et al. Effects of Mn partitioning on nanoscale precipitation and mechanical properties of ferritic steels strengthened by NiAl nanoparticles. Acta Mater. 84, 283–291 (2015)

    ADS  CAS  Article  Google Scholar 

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This research was supported by the National Natural Science Foundation of China (grant numbers 51531001, 51422101, 51671018, 51271212 and 51371003), the 111 Project (grant number B07003), the International S&T Cooperation Program of China (grant number 2015DFG52600), the Program for Changjiang Scholars and Innovative Research Team in University (grant number IRT_14R05) and the Projects of SKL-AMM-USTB (grant numbers 2016Z-04, 2016-09, 2016Z-16). Y.W. acknowledges the Top-Notch Young Talents Program and the Fundamental Research Funds for the Central Universities. We thank X. Xu at Tongling University, Z. Fan at the China Academy of Engineering Physics, Y. Qiao, L. You and G. Liu at the University of Science and Technology Beijing, and Y. Tian at Tohoku University for help with sample preparation and discussions. M.Y. and B.G. are grateful to U. Tezins and A. Sturm for their support of the focused ion beam and APT facilities at the Max-Planck-Institut für Eisenforschung. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract number DE-AC02-06CH11357.

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Authors and Affiliations



Z.L. designed the study. S.J., H.C., H.W, X.L. and Y. Wu carried out the main experiments. S.J., H.W., Z.L. and D.R. analysed the data and wrote the main draft of the paper. M.Y., B.G., D.P. and D.R. prepared the APT samples and interpreted the results. M.C. and A.H. conducted the STEM characterization. Y.Wa. conducted the synchrotron experiments. All authors contributed to the discussion of the results, and commented on the manuscript.

Corresponding author

Correspondence to Zhaoping Lu.

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Reviewer Information Nature thanks M. Moody, J. Morris Jr 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 Comparison of ultimate tensile stress and raw material cost between the typical ultrahigh-strength steels and the Ni(Al,Fe)-maraging steels.

The typical ultrahigh-strength steels include the commercially successful 18 wt% Ni maraging steels (Ni18Co9Mo5, wt%)1, Co-free maraging steels (Ni18.5Mo4Ti, wt%)2, W-strengthened steel (Ni19W4.2Ti1.2, wt%)29, and some commercial ultrahigh-strength steels (for example, Ni11Co13Cr3, wt%)30.

Extended Data Figure 2 The chemical compositions of the precipitates with different shapes and sites.

a, b, The selected precipitates (a) and corresponding chemical compositions (b). Precipitate A: round precipitates far away from Mo/C-decorated dislocations. Precipitate B: rod precipitates far away from Mo/C-decorated dislocations. Precipitate C: round/rod precipitates attached to Mo/C-decorated dislocations. The errors are standard deviations of the mean.

Extended Data Figure 3 Mass spectrum for the 40 precipitates from a subset.

Extended Data Figure 4 NbC precipitated in the solution-annealed specimen.

a, Scanning electron microscope image of the solution-annealed steel showing the presence of coarse primary NbC (0.5–2 μm; yellow circles). b, TEM image of the aged steel showing co-existence of NbC and Ni(Al,Fe) precipitates. The inset highlights the Ni(Al,Fe) precipitates in a local region of b. c, Energy dispersive spectroscopy and SAED patterns (the inset in c) of the large precipitate in b, confirming that the precipitate is MC-type (that is, a face-centred cubic metal carbide with metal-to-carbon ratio 1) NbC. Owing to its small volume fraction and large size, NbC was not observed in the APT characterization.

Extended Data Figure 5 Lattice parameters of the matrix and the B2 versus f(θ).

f(θ) = cos2(θ) × (1/sinθ + 1/θ)/2, where θ is the Bragg angle for each peak34. The best lattice parameter a was obtained at f(θ) = 0. The errors of the lattice parameters are associated with the errors in experimental measurements of θ.

Extended Data Table 1 Diffusion coefficients of Fe, Ni, Al and Mo in α-Fe at 500 °C

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Jiang, S., Wang, H., Wu, Y. et al. Ultrastrong steel via minimal lattice misfit and high-density nanoprecipitation. Nature 544, 460–464 (2017).

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