Hardening Effects of Precipitates with Different Shapes on the Twinning in Magnesium Alloys

  • Haidong FanEmail author
  • Jaafar A. El-Awady
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Molecular dynamics (MD) simulations were performed to quantify the effect of the precipitate shape on the interactions with extension twin boundaries in magnesium alloys. Three precipitate shapes, including plate-, cube- and rod-like, were studied. The simulation results indicate that the blocking effect of plate-like precipitate is weakly affected by the precipitate aspect ratio (plate width/plate thickness; so, cube-like precipitate is at aspect ratio of 1), while the rod-like precipitate has a hardening effect decreasing with the increasing aspect ratio (rod length/rod width). This suggests that the plate-like precipitate has an identical hardening effect as the cube-like precipitate and a higher effect than the rod-like precipitate.


Precipitation hardening Molecular dynamics Extension twinning Precipitate shape Magnesium alloys 



The financial support from National Natural Science Foundation of China (11672193, U1730106) is acknowledged. HF acknowledges the Alexander von Humboldt fellowship. Author JAE acknowledges support by the US Army Research Laboratory (#W911NF-12-2-0022).


  1. 1.
    Hutchinson CR, Nie JF, Gorsse S (2005) Modeling the precipitation processes and strengthening mechanisms in a Mg-Al-(Zn) AZ91 alloy. Metall. Mater. Trans. A 36 (8): 2093–2105CrossRefGoogle Scholar
  2. 2.
    Nie JF (2003) Effects of precipitate shape and orientation on dispersion strengthening in magnesium alloys. Scripta Mater. 48 (8): 1009–1015CrossRefGoogle Scholar
  3. 3.
    Agnew SR, Mulay RP, Polesak Iii FJ, Calhoun CA, Bhattacharyya JJ, Clausen B (2013) In situ neutron diffraction and polycrystal plasticity modeling of a Mg–Y–Nd–Zr alloy: Effects of precipitation on individual deformation mechanisms. Acta Mater. 61 (10): 3769–3780CrossRefGoogle Scholar
  4. 4.
    Stanford N, Geng J, Chun Y, Davies C, Nie J, Barnett M (2012) Effect of plate-shaped particle distributions on the deformation behaviour of magnesium alloy AZ91 in tension and compression. Acta Mater. 60 (1): 218–228CrossRefGoogle Scholar
  5. 5.
    Wang J, Stanford N (2015) Investigation of precipitate hardening of slip and twinning in Mg5%Zn by micropillar compression. Acta Mater. 100 53–63CrossRefGoogle Scholar
  6. 6.
    Jain J, Cizek P, Poole WJ, Barnett MR (2013) Precipitate characteristics and their effect on the prismatic-slip-dominated deformation behaviour of an Mg–6 Zn alloy. Acta Mater. 61 (11): 4091–4102CrossRefGoogle Scholar
  7. 7.
    Fan H, Zhu Y, El-Awady JA, Raabe D (2018) Precipitation hardening effects on extension twinning in magnesium alloys. Int. J. Plast. 106 186–202CrossRefGoogle Scholar
  8. 8.
    Plimpton S (1995) Fast Parallel Algorithms for Short-Range Molecular Dynamics. J. Comput. Phys. 117 (1): 1–19CrossRefGoogle Scholar
  9. 9.
    Liu X-Y, Adams JB, Ercolessi F, Moriarty JA (1996) EAM potential for magnesium from quantum mechanical forces. Model. Simul. Mater. Sci. Eng. 4 (3): 293–303CrossRefGoogle Scholar
  10. 10.
    Stukowski A (2010) Visualization and analysis of atomistic simulation data with OVITO–the Open Visualization Tool. Model. Simul. Mater. Sci. Eng. 18 (1): 015012CrossRefGoogle Scholar
  11. 11.
    Gharghouri M, Weatherly G, Embury J (1998) The interaction of twins and precipitates in a Mg-7.7 at.% Al alloy. Philos. Mag. A 78 (5): 1137–1149CrossRefGoogle Scholar
  12. 12.
    Fan H, Wang Q, Tian X, El-Awady JA (2017) Temperature effects on the mobility of pyramidal <c + a> dislocations in magnesium. Scripta Mater. 127 68–71CrossRefGoogle Scholar
  13. 13.
    Sim G-D, Kim G, Lavenstein S, Hamza MH, Fan H, El-Awady JA (2018) Anomalous hardening in magnesium driven by a size-dependent transition in deformation modes. Acta Mater. 144 (Supplement C): 11–20Google Scholar
  14. 14.
    Zu Q, Tang X-Z, Xu S, Guo Y-F (2017) Atomistic study of nucleation and migration of the basal/prismatic interfaces in Mg single crystals. Acta Mater. 130 310–318CrossRefGoogle Scholar
  15. 15.
    Jain J, Cizek P, Poole WJ, Barnett MR (2015) The role of back stress caused by precipitates on twinning in a Mg–6Zn alloy. Mater. Sci. Eng. A 647 66–73Google Scholar

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© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  1. 1.Department of MechanicsSichuan UniversityChengduChina
  2. 2.Department Microstructure Physics and Alloy DesignMax-Planck-Institut für Eisenforschung GmbHDüsseldorfGermany
  3. 3.Department of Mechanical Engineering, Whiting School of EngineeringThe Johns Hopkins UniversityBaltimoreUSA

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