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Mechanical properties and deformation mechanisms of gradient nanostructured metals and alloys

Nature Reviews Materials volume 5, pages 706–723 (2020)Cite this article

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Abstract

Inspired by the gradient structures of biological materials, researchers have explored compositional and structural gradients for about 40 years as an approach to enhance the properties of engineering materials, including metals and metallic alloys. The synthesis of various gradient nanostructured materials, such as gradient nanograined, nanolaminated nd nanotwinned metals and alloys, has provided new opportunities to understand gradient-related mechanical behaviour. These emerging gradient materials often exhibit unprecedented mechanical properties, such as strength–ductility synergy, extraordinary strain hardening, enhanced fracture and fatigue resistance, and remarkable resistance to wear and corrosion, which are not found in materials with homogeneous or random microstructures. This Review critically assesses the state of the art in the field of gradient nanostructured metallic materials, covering topics ranging from the fabrication and characterization of mechanical properties to underlying deformation mechanisms. We discuss various deformation behaviours induced by structural gradients, including stress and strain gradients, the accumulation and interaction of new dislocation structures, and unique interfacial behaviour, as well as providing insight into future directions for the development of gradient structured materials.

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Fig. 1: Types of structural and chemical gradients in typical gradient materials.
Fig. 2: Surface mechanical treatment methods.
Fig. 3: Microstructure of gradient nanograined, gradient nanolaminated and gradient nanotwinned metals.
Fig. 4: Comparison of the mechanical properties of gradient nanostructured and homogeneous metals and alloys.
Fig. 5: Comparison of fatigue and friction behaviour in gradient nanostructured and homogeneous metals and alloys.
Fig. 6: Deformation mechanisms in gradient nanostructured metals and alloys.
Fig. 7: Open issues and challenges for gradient nanostructured metals and alloys.

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References

  1. Liu, Z., Meyers, M. A., Zhang, Z. & Ritchie, R. O. Functional gradients and heterogeneities in biological materials: design principles, functions, and bioinspired applications. Prog. Mater. Sci. 88, 467–498 (2017).

    CAS  Google Scholar 

  2. Suresh, S. Graded materials for resistance to contact deformation and damage. Science 292, 2447–2451 (2001).

    CAS  Google Scholar 

  3. Fang, T., Tao, N. & Lu, K. Revealing extraordinary intrinsic tensile plasticity in gradient nano-grained copper. Science 331, 1587–1590 (2011). An early experimental report on gradient nanograined metals with extraordinary mechanical properties.

    CAS  Google Scholar 

  4. Wei, Y. et al. Evading the strength–ductility trade-off dilemma in steel through gradient hierarchical nanotwins. Nat. Commun. 5, 3580 (2014).

    Google Scholar 

  5. Wu, X., Jiang, P., Chen, L., Yuan, F. & Zhu, Y. T. Extraordinary strain hardening by gradient structure. Proc. Natl Acad. Sci. USA 111, 7197–7201 (2014).

    CAS  Google Scholar 

  6. Thevamaran, R. et al. Dynamic creation and evolution of gradient nanostructure in single-crystal metallic microcubes. Science 354, 312–316 (2016).

    CAS  Google Scholar 

  7. Cheng, Z., Zhou, H., Lu, Q., Gao, H. & Lu, L. Extra strengthening and work hardening in gradient nanotwinned metals. Science 362, eaau1925 (2018). An early experimental report on gradient nanotwinned metals with extraordinary mechanical properties.

    Google Scholar 

  8. Zhao, S. et al. Generating gradient germanium nanostructures by shock-induced amorphization and crystallization. Proc. Natl Acad. Sci. USA 114, 9791–9796 (2017).

    CAS  Google Scholar 

  9. Ma, X. et al. Mechanical properties of copper/bronze laminates: role of interfaces. Acta Mater. 116, 43–52 (2016).

    CAS  Google Scholar 

  10. Wu, X. et al. Synergetic strengthening by gradient structure. Mater. Res. Lett. 2, 185–191 (2014).

    CAS  Google Scholar 

  11. Ma, E. & Zhu, T. Towards strength–ductility synergy through the design of heterogeneous nanostructures in metals. Mater. Today 20, 323–331 (2017).

    CAS  Google Scholar 

  12. Yang, M., Pan, Y., Yuan, F., Zhu, Y. T. & Wu, X. Back stress strengthening and strain hardening in gradient structure. Mater. Res. Lett. 4, 145–151 (2016).

    CAS  Google Scholar 

  13. Lin, Y., Pan, J., Zhou, H., Gao, H. & Li, Y. Mechanical properties and optimal grain size distribution profile of gradient grained nickel. Acta Mater. 153, 279–289 (2018).

    CAS  Google Scholar 

  14. Roland, T., Retraint, D., Lu, K. & Lu, J. Fatigue life improvement through surface nanostructuring of stainless steel by means of surface mechanical attrition treatment. Scr. Mater. 54, 1949–1954 (2006). An early experimental study on enhancing fatigue properties of steel with a gradient nanograined surface layer.

    CAS  Google Scholar 

  15. Huang, H. W., Wang, Z. B., Lu, J. & Lu, K. Fatigue behaviors of AISI 316L stainless steel with a gradient nanostructured surface layer. Acta Mater. 87, 150–160 (2015).

    CAS  Google Scholar 

  16. Yang, L., Tao, N., Lu, K. & Lu, L. Enhanced fatigue resistance of Cu with a gradient nanograined surface layer. Scr. Mater. 68, 801–804 (2013).

    CAS  Google Scholar 

  17. Ma, Z. et al. Strength gradient enhances fatigue resistance of steels. Sci. Rep. 6, 22156 (2016).

    CAS  Google Scholar 

  18. Long, L. et al. Improved fatigue resistance of gradient nanograined Cu. Acta Mater. 166, 56–66 (2019). A recent experimental study on enhancing fatigue properties of gradient nanograined Cu.

    CAS  Google Scholar 

  19. Jing, L., Pan, Q., Long, J., Tao, N. & Lu, L. Effect of volume fraction of gradient nanograined layer on high-cycle fatigue behavior of Cu. Scr. Mater. 161, 74–77 (2019).

    CAS  Google Scholar 

  20. Chen, X., Han, Z., Li, X. & Lu, K. Lowering coefficient of friction in Cu alloys with stable gradient nanostructures. Sci. Adv. 2, e1601942 (2016). An experimental study on lowering the coefficient of friction in Cu alloys with a gradient nanograined surface layer.

    Google Scholar 

  21. Zeng, Z. et al. Gradient plasticity in gradient nano-grained metals. Extreme Mech. Lett. 8, 213–219 (2016).

    Google Scholar 

  22. Chen, W., You, Z., Tao, N., Jin, Z. & Lu, L. Mechanically-induced grain coarsening in gradient nano-grained copper. Acta Mater. 125, 255–264 (2017).

    CAS  Google Scholar 

  23. Long, J., Pan, Q., Tao, N. & Lu, L. Abnormal grain coarsening in cyclically deformed gradient nanograined Cu. Scr. Mater. 145, 99–103 (2018).

    CAS  Google Scholar 

  24. Li, J., Weng, G., Chen, S. & Wu, X. On strain hardening mechanism in gradient nanostructures. Int. J. Plast. 88, 89–107 (2017).

    CAS  Google Scholar 

  25. Lu, K. & Lu, J. Surface nanocrystallization (SNC) of metallic materials-presentation of the concept behind a new approach. J. Mater. Sci. Technol. 15, 193–197 (1999).

    CAS  Google Scholar 

  26. Wu, X. et al. Microstructure and evolution of mechanically-induced ultrafine grain in surface layer of Al-alloy subjected to USSP. Acta Mater. 50, 2075–2084 (2002).

    CAS  Google Scholar 

  27. Lu, K. & Lu, J. Nanostructured surface layer on metallic materials induced by surface mechanical attrition treatment. Mater. Sci. Eng. A 375, 38–45 (2004).

    Google Scholar 

  28. Zhu, K. Y., Vassel, A., Brisset, F., Lu, K. & Lu, J. Nanostructure formation mechanism of α-titanium using SMAT. Acta Mater. 52, 4101–4110 (2005).

    Google Scholar 

  29. Roland, T., Retraint, D., Lu, K. & Lu, J. Enhanced mechanical behavior of a nanocrystallised stainless steel and its thermal stability. Mater. Sci. Eng. A 445, 281–288 (2007).

    Google Scholar 

  30. Chen, A. Y. et al. The influence of strain rate on the microstructure transition of 304 stainless steel. Acta Mater. 59, 3697–3709 (2011).

    CAS  Google Scholar 

  31. Yang, D. K., Cizek, P., Fabijanic, D., Wang, J. T. & Hodgson, P. D. Work hardening in ultrafine-grained titanium: multilayering and grading. Acta Mater. 61, 2840–2852 (2013).

    CAS  Google Scholar 

  32. Hassani-Gangaraj, S. M., Cho, K. S., Voigt, H. J. L., Guagliano, M. & Schuh, C. A. Experimental assessment and simulation of surface nanocrystallization by severe shot peening. Acta Mater. 97, 105–115 (2015).

    CAS  Google Scholar 

  33. Meng, X. C. et al. The deformation behavior of AZ31 Mg alloy with surface mechanical attrition treatment. Mater. Sci. Eng. A 707, 636–646 (2017).

    CAS  Google Scholar 

  34. Li, W. L., Tao, N. R. & Lu, K. Fabrication of a gradient nano-micro-structured surface layer on bulk copper by means of a surface mechanical grinding treatment. Scr. Mater. 59, 546–549 (2008).

    CAS  Google Scholar 

  35. Liu, X. C., Zhang, H. W. & Lu, K. Strain-induced ultrahard and ultrastable nanolaminated structure in nickel. Science 342, 337–340 (2013).

    CAS  Google Scholar 

  36. Wang, H. T., Tao, N. R. & Lu, K. Architectured surface layer with a gradient nanotwinned structure in a Fe–Mn austenitic steel. Scr. Mater. 68, 22–27 (2013).

    CAS  Google Scholar 

  37. Liu, X. C., Zhang, H. W. & Lu, K. Formation of nanolaminated structure in an interstitial-free steel. Scr. Mater. 95, 54–57 (2015).

    CAS  Google Scholar 

  38. Liu, X. C., Zhang, H. W. & Lu, K. Formation of nano-laminated structure in nickel by means of surface mechanical grinding treatment. Acta Mater. 96, 24–36 (2015).

    CAS  Google Scholar 

  39. Xu, W., Liu, X. C. & Lu, K. Strain-induced microstructure refinement in pure Al below 100 nm in size. Acta Mater. 152, 138–147 (2018).

    CAS  Google Scholar 

  40. Ma, X. L. et al. Strain hardening and ductility in a coarse-grain/nanostructure laminate material. Scr. Mater. 103, 57–60 (2015).

    CAS  Google Scholar 

  41. Zhang, L. et al. Fabricating interstitial-free steel with simultaneous high strength and good ductility with homogeneous layer and lamella structure. Scr. Mater. 141, 111–114 (2017).

    CAS  Google Scholar 

  42. Nalla, R. K. et al. On the influence of mechanical surface treatments — deep rolling and laser shock peening — on the fatigue behavior of Ti–6Al–4V at ambient and elevated temperatures. Mater. Sci. Eng. A 355, 216–230 (2003).

    Google Scholar 

  43. Ye, C., Liao, Y. L., Suslov, S., Lin, D. & Cheng, G. J. Ultrahigh dense and gradient nano-precipitates generated by warm laser shock peening for combination of high strength and ductility. Mater. Sci. Eng. A 609, 195–203 (2014).

    CAS  Google Scholar 

  44. Luo, S. H. et al. Surface nanocrystallization of metallic alloys with different stacking fault energy induced by laser shock processing. Mater. Des. 104, 320–326 (2016).

    Google Scholar 

  45. Ren, X. D. et al. Microstructure evolution and grain refinement of Ti-6Al-4V alloy by laser shock processing. Appl. Surf. Sci. 363, 44–49 (2016).

    CAS  Google Scholar 

  46. Laine, S. J., Knowles, K. M., Doorbar, P. J., Cutts, R. D. & Rugg, D. Microstructural characterisation of metallic shot peened and laser shock peened Ti-6Al-4V. Acta Mater. 123, 350–361 (2017).

    CAS  Google Scholar 

  47. Li, J. J. et al. Eliminating deformation incompatibility in composites by gradient nanolayer architectures. Sci. Rep. 8, 16216 (2018).

    Google Scholar 

  48. Hofmann, D. C. et al. Developing gradient metal alloys through radial deposition additive manufacturing. Sci. Rep. 4, 5357 (2014).

    CAS  Google Scholar 

  49. Tan, X. P. et al. Graded microstructure and mechanical properties of additive manufactured Ti–6Al–4V via electron beam melting. Acta Mater. 97, 1–16 (2015).

    CAS  Google Scholar 

  50. Estrin, Y. & Vinogradov, A. Extreme grain refinement by severe plastic deformation: a wealth of challenging science. Acta Mater. 61, 782–817 (2013).

    CAS  Google Scholar 

  51. Wang, K., Tao, N. R., Liu, G., Lu, J. & Lu, K. Plastic strain-induced grain refinement at the nanometer scale in copper. Acta Mater. 54, 5281–5291 (2006).

    CAS  Google Scholar 

  52. Tao, N. R. & Lu, K. Nanoscale structural refinement via deformation twinning in face-centered cubic metals. Scr. Mater. 60, 1039–1043 (2009).

    CAS  Google Scholar 

  53. Lu, K. Making strong nanomaterials ductile with gradients. Science 345, 1455–1456 (2014).

    CAS  Google Scholar 

  54. Wu, X. L. et al. Heterogeneous lamella structure unites ultrafine-grain strength with coarse-grain ductility. Proc. Natl Acad. Sci. USA 112, 14501–14505 (2015).

    CAS  Google Scholar 

  55. Chen, A. Y., Liu, J. B., Wang, H. T., Lu, J. & Wang, Y. M. Gradient twinned 304 stainless steels for high strength and high ductility. Mater. Sci. Eng. A 667, 179–188 (2016).

    CAS  Google Scholar 

  56. Liu, Y. & Wei, Y. J. Gradient driven anomalous reversible plasticity in conventional magnesium alloys. Extreme Mech. Lett. 9, 158–164 (2016).

    Google Scholar 

  57. Moering, J. et al. Synergetic strengthening far beyond rule of mixtures in gradient structured aluminum rod. Scr. Mater. 122, 106–109 (2016).

    CAS  Google Scholar 

  58. Wu, X. L., Yang, M. X., Yuan, F. P., Chen, L. & Zhu, Y. T. Combining gradient structure and TRIP effect to produce austenite stainless steel with high strength and ductility. Acta Mater. 112, 337–346 (2016).

    CAS  Google Scholar 

  59. Chen, L., Yuan, F. P., Jiang, P., Xie, J. J. & Wu, X. L. Mechanical properties and deformation mechanism of Mg-Al-Zn alloy with gradient microstructure in grain size and orientation. Mater. Sci. Eng. A 694, 98–109 (2017).

    CAS  Google Scholar 

  60. Wang, Y. et al. Optimal stress and deformation partition in gradient materials for better strength and tensile ductility: a numerical investigation. Sci. Rep. 7, 10954 (2017).

    Google Scholar 

  61. Fu, Z. Q. et al. Engineering heterostructured grains to enhance strength in a single-phase high-entropy alloy with maintained ductility. Mater. Res. Lett. 6, 634–640 (2018).

    CAS  Google Scholar 

  62. Han, Z. H., Liang, S., Yang, J., Wei, R. & Zhang, C. J. A superior combination of strength-ductility in CoCrFeNiMn high-entropy alloy induced by asymmetric rolling and subsequent annealing treatment. Mater. Charact. 145, 619–626 (2018).

    CAS  Google Scholar 

  63. Huang, C. X. et al. Interface affected zone for optimal strength and ductility in heterogeneous laminate. Mater. Today 21, 713–719 (2018).

    CAS  Google Scholar 

  64. Ma, Z. W. et al. Cryogenic temperature toughening and strengthening due to gradient phase structure. Mater. Sci. Eng. A 712, 358–364 (2018).

    CAS  Google Scholar 

  65. Wang, Y. F., Huang, C. X., Wang, M. S., Li, Y. S. & Zhu, Y. T. Quantifying the synergetic strengthening in gradient material. Scr. Mater. 150, 22–25 (2018).

    CAS  Google Scholar 

  66. Yuan, F. P. et al. Ductility by shear band delocalization in the nano-layer of gradient structure. Mater. Res. Lett. 7, 12–17 (2018).

    Google Scholar 

  67. Niu, G., Wu, H. B., Zhang, D., Gong, N. & Tang, D. Heterogeneous nano/ultrafine-grained medium Mn austenitic stainless steel with high strength and ductility. Mater. Sci. Eng. A 725, 187–195 (2018).

    CAS  Google Scholar 

  68. Cheng, Z. & Lu, L. The effect of gradient order on mechanical behaviors of gradient nanotwinned Cu. Scr. Mater. 164, 130–134 (2019).

    CAS  Google Scholar 

  69. Lee, H. H., Yoon, J. I., Park, H. K. & Kim, H. S. Unique microstructure and simultaneous enhancements of strength and ductility in gradient-microstructured Cu sheet produced by single-roll angular-rolling. Acta Mater. 166, 638–649 (2019).

    CAS  Google Scholar 

  70. Wu, S. W. et al. Enhancement of strength-ductility trade-off in a high-entropy alloy through a heterogeneous structure. Acta Mater. 165, 444–458 (2019).

    CAS  Google Scholar 

  71. Zhu, L. L. et al. Static and dynamic mechanical behaviors of gradient-nanotwinned stainless steel with a composite structure: experiments and modeling. Int. J. Plast. 114, 272–288 (2019).

    CAS  Google Scholar 

  72. Long, Q. Y., Lu, J. X. & Fang, T. H. Microstructure and mechanical properties of AISI 316L steel with an inverse gradient nanostructure fabricated by electro-magnetic induction heating. Mater. Sci. Eng. A 751, 42–50 (2019).

    CAS  Google Scholar 

  73. Wu, X. L. & Zhu, Y. T. Heterogeneous materials: a new class of materials with unprecedented mechanical properties. Mater. Res. Lett. 5, 527–532 (2017).

    CAS  Google Scholar 

  74. Ding, J. et al. Mechanical behavior of structurally gradient nickel alloy. Acta Mater. 149, 57–67 (2018).

    CAS  Google Scholar 

  75. Zhou, X., Li, X. Y. & Lu, K. Strain hardening in gradient nano-grained Cu at 77K. Scr. Mater. 153, 6–9 (2018).

    CAS  Google Scholar 

  76. Bian, X. D., Yuan, F. P., Zhu, Y. T. & Wu, X. L. Gradient structure produces superior dynamic shear properties. Mater. Res. Lett. 5, 501–507 (2017).

    CAS  Google Scholar 

  77. Shao, C. W. et al. Simultaneous improvement of strength and plasticity: additional work-hardening from gradient microstructure. Acta Mater. 145, 413–428 (2018).

    CAS  Google Scholar 

  78. Zhang, P. & Lindemann, J. Influence of shot peening on high cycle fatigue properties of the high-strength wrought magnesium alloy AZ80. Scr. Mater. 52, 485–490 (2005).

    CAS  Google Scholar 

  79. Liu, W. C. et al. Improvement of fatigue properties by shot peening for Mg–10Gd–3Y alloys under different conditions. Mater. Sci. Eng. A 528, 5935–5944 (2011).

    CAS  Google Scholar 

  80. Nazari, A. Modeling fracture toughness of ferritic and austenitic functionally graded steel based on the strain gradient plasticity theory. Comp. Mater. Sci. 50, 3238–3244 (2011).

    CAS  Google Scholar 

  81. Nielsen, K. L., Niordson, C. F. & Hutchinson, J. W. Strain gradient effects on steady state crack growth in rate-sensitive materials. Eng. Fract. Mech. 96, 61–71 (2012).

    Google Scholar 

  82. Trudel, A., Lévesque, M. & Brochu, M. Microstructural effects on the fatigue crack growth resistance of a stainless steel CA6NM weld. Eng. Fract. Mech. 115, 60–72 (2014).

    Google Scholar 

  83. Zhang, K., Wang, Z. B. & Lu, K. Enhanced fatigue property by suppressing surface cracking in a gradient nanostructured bearing steel. Mater. Res. Lett. 5, 258–266 (2016).

    Google Scholar 

  84. Pandey, V., Chattopadhyay, K., Santhi Srinivas, N. C. & Singh, V. Role of ultrasonic shot peening on low cycle fatigue behavior of 7075 aluminium alloy. Int. J. Fatigue 103, 426–435 (2017).

    CAS  Google Scholar 

  85. Zhang, S. J. et al. Fatigue crack growth behavior in gradient microstructure of hardened surface layer for an axle steel. Mater. Sci. Eng. A 700, 66–74 (2017).

    CAS  Google Scholar 

  86. Zhou, J., Sun, Z., Kanouté, P. & Retraint, D. Effect of surface mechanical attrition treatment on low cycle fatigue properties of an austenitic stainless steel. Int. J. Fatigue 103, 309–317 (2017).

    CAS  Google Scholar 

  87. Giang, N. A., Seupel, A., Kuna, M. & Hütter, G. Dislocation pile-up and cleavage: effects of strain gradient plasticity on micro-crack initiation in ferritic steel. Int. J. Fract. 214, 1–15 (2018).

    CAS  Google Scholar 

  88. Martínez-Pañeda, E., Deshpande, V. S., Niordson, C. F. & Fleck, N. A. The role of plastic strain gradients in the crack growth resistance of metals. J. Mech. Phys. Solids 126, 136–150 (2019).

    Google Scholar 

  89. Wang, Y. et al. The influence of combined gradient structure with residual stress on crack-growth behavior in medium carbon steel. Eng. Fract. Mech. 209, 369–381 (2019).

    Google Scholar 

  90. Long, J. Z., Pan, Q. S., Tao, N. R. & Lu, L. Residual stress induced tension-compression asymmetry of gradient nanograined copper. Mater. Res. Lett. 6, 456–461 (2018).

    CAS  Google Scholar 

  91. Lei, Y. B., Wang, Z. B., Xu, J. L. & Lu, K. Simultaneous enhancement of stress- and strain-controlled fatigue properties in 316L stainless steel with gradient nanostructure. Acta Mater. 168, 133–142 (2019).

    CAS  Google Scholar 

  92. Zhang, Y. S., Han, Z., Wang, K. & Lu, K. Friction and wear behaviors of nanocrystalline surface layer of pure copper. Wear 260, 942–948 (2006).

    CAS  Google Scholar 

  93. Prakash, N. A., Gnanamoorthy, R. & Kamaraj, M. Friction and wear behavior of surface nanocrystallized aluminium alloy under dry sliding condition. Mater. Sci. Eng. B 168, 176–181 (2010).

    CAS  Google Scholar 

  94. Amanov, A., Lee, S. W. & Pyun, Y. S. Low friction and high strength of 316L stainless steel tubing for biomedical applications. Mater. Sci. Eng. C. 71, 176–185 (2017).

    CAS  Google Scholar 

  95. Bernoulli, D., Cao, S. C., Lu, J. & Dao, M. Enhanced repeated frictional sliding properties in 304 stainless steel with a gradient nanostructured surface. Surf. Coat. Technol. 339, 14–19 (2018).

    CAS  Google Scholar 

  96. Ge, M. Z. et al. Wear behavior of Mg-3Al-1Zn alloy subjected to laser shock peening. Surf. Coat. Technol. 337, 501–509 (2018).

    CAS  Google Scholar 

  97. Balusamy, T. et al. Influence of surface mechanical attrition treatment (SMAT) on the corrosion behaviour of AISI 304 stainless steel. Corros. Sci. 74, 332–344 (2013).

    CAS  Google Scholar 

  98. Hao, Y., Deng, B., Zhong, C., Jiang, Y. & Li, J. Effect of surface mechanical attrition treatment on corrosion behavior of 316 stainless steel. J. Iron Steel Res. Int. 16, 68–72 (2009).

    CAS  Google Scholar 

  99. Li, N. N., Shi, S. Q., Luo, J. L., Lu, J. & Wang, N. Effects of surface nanocrystallization on the corrosion behaviors of 316L and alloy 690. Surf. Coat. Technol. 309, 227–231 (2017).

    CAS  Google Scholar 

  100. Meyers, M. A., Mishra, A. & Benson, D. J. Mechanical properties of nanocrystalline materials. Prog. Mater. Sci. 51, 427–556 (2006).

    CAS  Google Scholar 

  101. Lu, L., Shen, Y., Chen, X., Qian, L. & Lu, K. Ultrahigh strength and high electrical conductivity in copper. Science 304, 422–426 (2004).

    CAS  Google Scholar 

  102. Lu, L., Chen, X., Huang, X. & Lu, K. Revealing the maximum strength in nano-twinned copper. Science 323, 607–610 (2009).

    CAS  Google Scholar 

  103. Anderoglu, O. et al. Epitaxial nanotwinned Cu films with high strength and high conductivity. Appl. Phys. Lett. 93, 083108 (2008).

    Google Scholar 

  104. Bufford, D., Wang, H. & Zhang, X. High strength, epitaxial nanotwinned Ag films. Acta Mater. 59, 93–101 (2011).

    CAS  Google Scholar 

  105. Idrissi, H., Wang, B., Colla, M. S. & Raskin, J. P. Ultrahigh strain hardening in thin palladium films with nanoscale twins. Adv. Mater. 23, 2119–2122 (2011).

    CAS  Google Scholar 

  106. Wang, Y. M. et al. Defective twin boundaries in nanotwinned metals. Nat. Mater. 12, 697–702 (2013).

    CAS  Google Scholar 

  107. Li, Q. et al. High-strength nanotwinned Al alloys with 9R phase. Adv. Mater. 30, 1704629 (2018).

    Google Scholar 

  108. Jang, D., Li, X., Gao, H. & Greer, J. R. Deformation mechanisms in nanotwinned metal nanopillars. Nat. Nanotechnol. 7, 594–601 (2012).

    CAS  Google Scholar 

  109. Zhu, T., Li, J., Samanta, A., Kim, H. G. & Suresh, S. Interfacial plasticity governs strain rate sensitivity and ductility in nanostructured metals. Proc. Natl Acad. Sci. USA 104, 3031–3036 (2007).

    CAS  Google Scholar 

  110. Li, X., Wei, Y., Lu, L., Lu, K. & Gao, H. Dislocation nucleation governed softening and maximum strength in nano-twinned metals. Nature 464, 877–880 (2010).

    CAS  Google Scholar 

  111. You, Z. et al. Plastic anisotropy and associated deformation mechanisms in nanotwinned metals. Acta Mater. 61, 217–227 (2013).

    CAS  Google Scholar 

  112. Pan, Q., Zhou, H., Lu, Q., Gao, H. & Lu, L. History-independent cyclic response of nanotwinned metals. Nature 551, 214–217 (2017).

    CAS  Google Scholar 

  113. Zhou, H., Li, X., Qu, S., Yang, W. & Gao, H. A jogged dislocation governed strengthening mechanism in nanotwinned metals. Nano Lett. 14, 5075–5080 (2014).

    CAS  Google Scholar 

  114. Zhou, H., Qu, S. & Yang, W. Toughening by nano-scaled twin boundaries in nanocrystals. Model. Simul. Mater. Sci. Eng. 18, 065002 (2010).

    Google Scholar 

  115. Sansoz, F., Lu, K., Zhu, T. & Misra, A. Strengthening and plasticity in nanotwinned metals. MRS Bull. 41, 292–297 (2016).

    CAS  Google Scholar 

  116. Sun, L., He, X. & Lu, J. Nanotwinned and hierarchical nanotwinned metals: a review of experimental, computational and theoretical efforts. npj Comp. Mater. 4, 6 (2018).

    Google Scholar 

  117. Qu, S. et al. Microstructural evolution and mechanical properties of Cu–Al alloys subjected to equal channel angular pressing. Acta Mater. 57, 1586–1601 (2009).

    CAS  Google Scholar 

  118. Zhang, Z. et al. Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium entropy alloy. Nat. Commun. 8, 14390 (2017).

    CAS  Google Scholar 

  119. Kou, H. N., Lu, J. & Li, Y. High-strength and high-ductility nanostructured and amorphous metallic materials. Adv. Mater. 26, 5518–5524 (2014).

    CAS  Google Scholar 

  120. Yuan, F. P. & Wu, X. L. Size effects of primary/secondary twins on the atomistic deformation mechanisms in hierarchically nanotwinned metals. J. Appl. Phys. 113, 203516 (2013).

    Google Scholar 

  121. Yuan, F. P. & Wu, X. L. Atomistic scale fracture behaviours in hierarchically nanotwinned metals. Philos. Mag. 93, 3248–3259 (2013).

    CAS  Google Scholar 

  122. Yuan, F. P., Chen, L., Jiang, P. & Wu, X. L. Twin boundary spacing effects on shock response and spall behaviors of hierarchically nanotwinned fcc metals. J. Appl. Phys. 115, 063509 (2014).

    Google Scholar 

  123. Hart, E. W. Theory of the tensile test. Acta Metall. 15, 351–355 (1967).

    CAS  Google Scholar 

  124. Hutchinson, J. W. & Neale, K. W. Influence of strain-rate sensitivity on necking under uniaxial tension. Acta Metall. 25, 839–846 (1977).

    CAS  Google Scholar 

  125. Yasnikov, I. S., Vinogradov, A. & Estrin, Y. Revisiting the Considère criterion from the viewpoint of dislocation theory fundamentals. Scr. Mater. 76, 37–40 (2014).

    CAS  Google Scholar 

  126. Gupta, R. K. & Birbilis, N. The influence of nanocrystalline structure and processing route on corrosion of stainless steel: a review. Corros. Sci. 92, 1–15 (2015).

    CAS  Google Scholar 

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

    CAS  Google Scholar 

  128. Zhao, J. et al. Multiple mechanism based constitutive modeling of gradient nanograined material. Inter. J. Plast. 125, 314–330 (2019).

    Google Scholar 

  129. Yang, M. et al. Residual stress provides significant strengthening and ductility in gradient structured materials. Mater. Res. Lett. 7, 433–438 (2019).

    CAS  Google Scholar 

  130. Zhu, Y. & Wu, X. Perspective on hetero-deformation induced (HDI) hardening and back stress. Mater. Res. Lett. 7, 393–398 (2019).

    Google Scholar 

  131. Evans, A. G. & Hutchinson, J. W. A critical assessment of theories of strain gradient plasticity. Acta Mater. 57, 1675–1688 (2009).

    CAS  Google Scholar 

  132. Fleck, N. A., Muller, G. M., Ashby, M. F. & Hutchinson, J. W. Strain gradient plasticity-theory and experiment. Acta Metall. Mater. 42, 475–487 (1994).

    CAS  Google Scholar 

  133. Nix, W. D. & Gao, H. J. Indentation size effects in crystalline materials: a law for strain gradient plasticity. J. Mech. Phys. Solids 46, 411–425 (1998).

    CAS  Google Scholar 

  134. Ashby, M. F. The deformation of plastically non-homogeneous materials. Phil. Mag. 21, 399–424 (1970).

    CAS  Google Scholar 

  135. Gao, H., Huang, Y., Nix, W. D. & Hutchinson, J. W. Mechanism-based strain gradient plasticity-I. Theory. J. Mech. Phys. Solids 47, 1239–1263 (1999).

    Google Scholar 

  136. Huang, Y., Gao, H., Nix, W. D. & Hutchinson, J. W. Mechanism-based strain gradient plasticity-II. Analysis. J. Mech. Phys. Solids 48, 99–128 (2000).

    Google Scholar 

  137. Cao, P. The strongest size in gradient nanograined metals. Nano Lett. 20, 1440–1446 (2020).

    CAS  Google Scholar 

  138. Liu, Y., Bufford, D., Wang, H., Sun, C. & Zhang, X. Mechanical properties of highly textured Cu/Ni multilayers. Acta Mater. 59, 1924–1933 (2011).

    CAS  Google Scholar 

  139. Wang, J., Beyerlein, I. J., Mara, N. A. & Bhattacharyya, D. Interface-facilitated deformation twinning in copper within submicron Ag–Cu multilayered composites. Scr. Mater. 64, 1083–1386 (2011).

    CAS  Google Scholar 

  140. Bufford, D., Bi, Z., Jia, Q. X., Wang, H. & Zhang, X. Nanotwins and stacking faults in high-strength epitaxial Ag/Al multilayer films. Appl. Phys. Lett. 101, 223112 (2012).

    Google Scholar 

  141. Zheng, S. et al. High strength and thermal stability due to twin-induced interfaces. Nat. Commun. 4, 1696 (2013).

    Google Scholar 

  142. Zheng, S. et al. Plastic instability mechanisms in bimetallic nanolayered composites. Acta Mater. 79, 282–291 (2014).

    CAS  Google Scholar 

  143. Wang, J. & Misra, A. An overview of interface-dominated deformation mechanisms in metallic multilayers. Curr. Opin. Solid State Mater. Sci. 15, 20–28 (2011).

    CAS  Google Scholar 

  144. Wang, J., Zhou, Q., Shao, S. & Misra, A. Strength and plasticity of nanolaminated materials. Mater. Res. Lett. 5, 1–19 (2017).

    Google Scholar 

  145. Regueiro, R. A., Bammann, D. J., Marin, E. B. & Garikipati, K. A nonlocal phenomenological anisotropic finite deformation plasticity model accounting for dislocation defects. J. Eng. Mater. Technol. 124, 380–387 (2002).

    Google Scholar 

  146. Shizawa, K. & Zbib, H. M. A thermodynamical theory of gradient elastoplasticity with dislocation density tensor. I: fundamentals. Int. J. Plast. 15, 899–938 (1999).

    Google Scholar 

  147. Yefimov, S., Groma, I. & van der Giessen, E. A comparison of a statistical-mechanics based plasticity model with discrete dislocation plasticity calculations. J. Mech. Phys. Solids 52, 279–300 (2004).

    Google Scholar 

  148. Han, C. S., Gao, H., Huang, Y. & Nix, W. D. Mechanism-based strain gradient crystal plasticity. I. Theory. J. Mech. Phys. Solids 53, 1188–1203 (2005).

    Google Scholar 

  149. Bayley, C. J., Brekelmans, W. A. M. & Geers, M. G. D. A comparison of dislocation induced back stress formulations in strain gradient crystal plasticity. Int. J. Solids Struct. 43, 7268–7286 (2006).

    Google Scholar 

  150. Winning, M., Gottstein, G. & Shvindlerman, L. S. Stress induced grain boundary motion. Acta Mater. 49, 211–219 (2001).

    CAS  Google Scholar 

  151. Cahn, J. W., Mishin, Y. & Suzuki, A. Coupling grain boundary motion to shear deformation. Acta Mater. 54, 4953–4975 (2006).

    CAS  Google Scholar 

  152. Rupert, T. J., Gianola, D. S., Gan, Y. & Hemker, K. J. Experimental observations of stress-driven grain boundary migration. Science 326, 1686–1690 (2009).

    CAS  Google Scholar 

  153. Gottstein, G. & Molodov, D. A. Grain boundary migration in metals: recent developments. Inter. Sci. 6, 7–22 (1998).

    CAS  Google Scholar 

  154. Zhou, X., Li, X. & Lu, K. Size dependence of grain boundary migration in metals under mechanical loading. Phys. Rev. Lett. 122, 12601 (2019).

    Google Scholar 

  155. Pilania, G., Wang, C., Jiang, X., Rajasekaran, S. & Ramprasad, R. Accelerating materials property predictions using machine learning. Sci. Rep. 3, 2810 (2013).

    Google Scholar 

  156. Meredig, B. et al. Combinatorial screening for new materials in unconstrained composition space with machine learning. Phys. Rev. B 89, 094104 (2014).

    Google Scholar 

  157. Raccugli, P. et al. Machine-learning-assisted materials discovery using failed experiments. Nature 533, 73–76 (2016).

    Google Scholar 

  158. Butler, K. T., Davies, D. W., Cartwright, H., Isayev, O. & Walsh, A. Machine learning for molecular and materials science. Nature 559, 547–555 (2018).

    CAS  Google Scholar 

  159. Wu, G. et al. Hierarchical nanostructured aluminum alloy with ultrahigh strength and large plasticity. Nat. Commun. 10, 5099 (2019).

    Google Scholar 

  160. Wu, X. et al. Nanodomained nickel unite nanocrystal strength with coarse-grain ductility. Sci. Rep. 5, 11728 (2015).

    Google Scholar 

  161. Xu, Y., Fu, Y. & Chen, H. Planar gradient metamaterials. Nat. Rev. Mater. 1, 16067 (2016).

    CAS  Google Scholar 

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Acknowledgements

The authors gratefully acknowledge financial support from the National Natural Science Foundation of China (grant no. 51420105001). H.G. has also received funding from the US National Science Foundation (grant no. DMR-1709318). L.L. thanks the National Natural Science Foundation of China (grant nos 51471172, 51931010 and U1608257), the Key Research Program of Frontier Sciences and the International Partnership Program (grant no. GJHZ2029) of the Chinese Academy of Sciences, and the LiaoNing Revitalization Talents Program (grant no. XLYC1802026). X.L. acknowledges financial support from the National Natural Science Foundation of China (grant nos 11522218 and 11720101002), the Beijing Natural Science Foundation (grant no. Z180014) and the National Science and Technology Major Project (grant no. 2017-VI-0003–0073).

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Authors and Affiliations

  1. Center for Advanced Mechanics and Materials, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing, China

    Xiaoyan Li, Jianguo Li & Xuan Zhang

  2. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, China

    Lei Lu

  3. School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, Singapore, Singapore

    Huajian Gao

  4. Institute of High Performance Computing, A*STAR, Singapore, Singapore

    Huajian Gao

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X.L., L.L. and H.G. discussed the content. All authors contributed to the writing, reviewing and editing of the manuscript.

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Li, X., Lu, L., Li, J. et al. Mechanical properties and deformation mechanisms of gradient nanostructured metals and alloys. Nat Rev Mater 5, 706–723 (2020). https://doi.org/10.1038/s41578-020-0212-2

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