Advertisement

Journal of Materials Science

, Volume 50, Issue 8, pp 3212–3225 | Cite as

Microstructure evolution and mechanical properties of a submerged friction-stir-processed AZ91 magnesium alloy

  • Fang Chai
  • Datong Zhang
  • Yuanyuan Li
  • Wen Zhang
Original Paper

Abstract

AZ91 casting alloy is subjected to friction stir processing (FSP) in air (NFSP) and under water (SFSP). The thermal histories of the two FSP procedures are measured, and their effects on microstructure evolution and mechanical properties of the experimental materials are investigated. Compared with NFSP, the peak temperature during SFSP is about 150 °C lower and a much higher cooling rate of 13 °C/s is gained. Both NFSP and SFSP produce uniform recrystallized microstructures with dominant high-angle grain boundaries. The average grain size of the NFSP specimen is 7.8 μm, and SFSP results in further grain refinement with a grain size of 1.2 μm. The observed grain sizes of the two FSP specimens match well with the predicted values calculated by the Derby–Ashby model. TEM observation, temperature data, and model criterion indicate that the grain refinement mechanism during NFSP is attributed to continuous dynamic recrystallization (DRX), while continuous DRX and discontinuous DRX affect during SFSP. The mechanical properties of the SFSP alloy are much higher due to finer microstructure.

Keywords

Magnesium Alloy Friction Stir Processing Misorientation Angle AZ91 Magnesium Alloy Refinement Mechanism 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

This work was sponsored by the Fundamental Research Funds for the Central Universities (No. 2014ZG0028) and Research Fund for the Doctoral Program of Higher Education of China (No. 20130172110044)

References

  1. 1.
    Mordike BL, Ebert T (2001) Magnesium properties-applications-potential. Mater Sci Eng A 302:37–45CrossRefGoogle Scholar
  2. 2.
    Jin L, Lin DL, Mao DM, Zeng XQ, Ding WJ (2005) Mechanical properties and microstructure of AZ31 Mg alloy processed by two-step equal channel angular extrusion. Mater Lett 59:2267–2270CrossRefGoogle Scholar
  3. 3.
    Kim WJ, An CW, Kim YS, Hong SI (2002) Mechanical properties and microstructures of an AZ61 Mg alloy produced by equal channel angular pressing. Scripta Mater 47:39–44CrossRefGoogle Scholar
  4. 4.
    Pérez-Prado MT, del Valle JA, Ruano OA (2004) Grain refinement of Mg-Al-Zn alloys via accumulative roll bonding. Scripta Mater 51:1093–1097CrossRefGoogle Scholar
  5. 5.
    Mishra RS, Ma ZY (2005) Friction stir welding and processing. Mater Sci Eng R 50:1–78CrossRefGoogle Scholar
  6. 6.
    Thomas WM, Nicholas ED, Needham JC, Church MG, Templesmith P, Dawes CJ (1991) GB Patent Application, No. 91259788Google Scholar
  7. 7.
    Feng AH, Xiao BL, Ma ZY, Chen RS (2009) Effect of friction stir processing produced on microstructure and mechanical properties of Mg-Al-Zn casting. Metall Mater Trans A 40:2447–2456CrossRefGoogle Scholar
  8. 8.
    Razal Rose A, Manisekar K, Balasubramanian V (2012) Influence of welding speed on tensile properties of friction stir welded AZ61 magnesium alloy. J Mater Eng Perform 21:257–265CrossRefGoogle Scholar
  9. 9.
    Feng AH, Ma ZY (2007) Enhanced mechanical properties of Mg-Al-Zn cast alloy via friction stir processing. Scripta Mater 56:397–400CrossRefGoogle Scholar
  10. 10.
    Cavaliere P, De Marco PP (2007) Fatigue behavior of friction stir processed AZ91 magnesium alloy produced by high pressure die casting. Mater Charact 58:226–232CrossRefGoogle Scholar
  11. 11.
    Yuan W, Panigahi SK, Mishra RS (2013) Achieving high strength and high ductility in friction stir processed cast magnesium alloy. Metall Mater Trans A 44:3675–3684CrossRefGoogle Scholar
  12. 12.
    Hung FY, Shih CC, Chen LH, Lui TS (2007) Microstructures and high temperature mechanical properties of friction stirred AZ31-Mg alloy. J Alloy Compd 428:106–114CrossRefGoogle Scholar
  13. 13.
    Xiao BL, Yang Q, Wang J, Wang WG, Xie GM, Ma ZY (2011) Enhanced mechanical properties of Mg-Gd-Y-Zr casting via friction stir processing. J Alloy Compd 509:2879–2884CrossRefGoogle Scholar
  14. 14.
    Yang Q, Xiao BL, Ma ZY (2012) Influence of process parameters on microstructure and mechanical properties of friction-stir-processed Mg-Gd-Y-Zr casting. Metall Mater Trans A 43:2094–2109CrossRefGoogle Scholar
  15. 15.
    Yang Q, Xiao BL, Wang D, Zheng MY, Wu K, Ma ZY (2013) Formation of long-period stacking ordered phase only within grains in Mg-Gd-Y-Zn-Zr casting by friction stir processing. J Alloy Compd 581:585–589CrossRefGoogle Scholar
  16. 16.
    Sato YS, Urata M, Kokawa H (2012) Parameters controlling microstructures and hardness during friction-stir welding of precipitation-hardenable aluminum alloy 6063. Metall Mater Trans A 33:625–635CrossRefGoogle Scholar
  17. 17.
    Liu FC, Tan MJ, Liao J, Ma ZY, Meng Q, Nakata K (2013) Microstructural evolution and superplastic behavior in friction stir processed Mg-Li-Al-Zn alloy. J Mater Sci 48:8539–8546. doi: 10.1007/s10853-013-7672-3 CrossRefGoogle Scholar
  18. 18.
    Hofmann DC, Vecchio KS (2005) Submerged friction stir processing (SFSP): an improved method for creating ultrafine grained bulk materials. Mater Sci Eng A 402:234–241CrossRefGoogle Scholar
  19. 19.
    Su JQ, Nelson TW, Sterling CJ (2005) Friction stir processing of large-area bulk UFG aluminum alloys. Scripta Mater 52:135–140CrossRefGoogle Scholar
  20. 20.
    Darras B, Kishta E (2013) Submerged friction stir processing of AZ31 magnesium alloy. Mater Des 47:133–137CrossRefGoogle Scholar
  21. 21.
    Jata KV, Semiatin SL (2000) Continuous dynamic recrystallization during friction stir welding of high strength aluminum alloys. Scripta Mater 43:743–749CrossRefGoogle Scholar
  22. 22.
    Heinz B, Skrotzki B (2002) Characterization of a friction stir welded aluminum alloy 6013. Metall Mater Trans B 33:489–498CrossRefGoogle Scholar
  23. 23.
    Rhodes CG, Mahoney MW, Bingel WH, Calabrese M (2003) Fine-grain evolution in friction-stir processed 7050 aluminum. Scripta Mater 48:1451–1455CrossRefGoogle Scholar
  24. 24.
    Su JQ, Nelson TW, Sterling CJ (2003) A new route to bulk nanocrystalline materials. J Mater Res 18:1757–1760CrossRefGoogle Scholar
  25. 25.
    Sastry DH, Prasad Y, Vasu KI (1969) On the stacking fault energies of some close-packed metals. Scripta Metall 3:927–929CrossRefGoogle Scholar
  26. 26.
    Feng AH, Ma ZY (2009) Microstructure evolution of cast Mg-Al-Zn during friction stir processing and subsequent aging. Acta Mater 57:4248–4260CrossRefGoogle Scholar
  27. 27.
    Chai F, Zhang DT, Li YY (2014) Effect of thermal history on microstructures and mechanical properties of AZ31 magnesium alloy prepared by friction stir processing. Materials 7:1573–1589CrossRefGoogle Scholar
  28. 28.
    Celotto S, Bastow TJ (2001) Study of precipitation in aged binary Mg-Al and ternary Mg-Al-Zn alloys using 27Al NMR spectroscopy. Acta Mater 49:41–45CrossRefGoogle Scholar
  29. 29.
    Schmidt H, Hattel J, Wert J (2004) An analytical model for the heat generation in friction stir welding. Modelling Simul Mater Sci Eng 12:143–157CrossRefGoogle Scholar
  30. 30.
    Hofmann DC, Vecchio KS (2007) Thermal history analysis of friction stir processed and submerged friction stir processed aluminum. Mater Sci Eng A 465:165–175CrossRefGoogle Scholar
  31. 31.
    Tang W, Guo X, McClure JC, Murr LE, Nunes A (1988) Heat input and temperature distribution in friction stir welding. J Mater Process Manuf Sci 7:163–172CrossRefGoogle Scholar
  32. 32.
    Arbegast MJ, Hartley PJ (1988) In: Proceedings of the fifth international conference on trends in welding research, Pine Mountain, GA, USAGoogle Scholar
  33. 33.
    Derby B, Ashby MF (1987) On dynamic recrystallization. Scripta Metall 21:879–884CrossRefGoogle Scholar
  34. 34.
    Frost HJ, Ashby MF (1982) Deformation Mechanism Maps. Pergamon Press, OxfordGoogle Scholar
  35. 35.
    Hines JA, Vecchio KS (1997) Recrystallization kinetics within adiabatic shear bands. Acta Mater 45:635–649CrossRefGoogle Scholar
  36. 36.
    Humphreys FJ, Hatherly M (1995) Recrystallization and related annealing phenomena, 2nd edn. Elsevier, Oxford, pp 229–232Google Scholar
  37. 37.
    Galiyev A, Kaibyshev R, Gottstein G (2001) Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Mater 49:1199–1207CrossRefGoogle Scholar
  38. 38.
    Chang CI, Du XH, Huang JC (2008) Processing nanograined microstructure in Mg-Al-Zn alloy by two-pass friction stir processing. Scripta Mater 59:356–359CrossRefGoogle Scholar
  39. 39.
    Sitdikov O, Kaibyshev R (2001) Dynamic recrystallization in pure magnesium. Mater Trans 42:1928–1937CrossRefGoogle Scholar
  40. 40.
    Liu CM, Liu ZJ, Zhu XR, Zhou HT (2006) Research and development progress of dynamic recrystallization in pure magnesium and its alloys. Trans Nonferrous Met Soc China 16:1–12 (In Chinese)CrossRefGoogle Scholar
  41. 41.
    Chang CI, Lee CJ, Huang JC (2004) Relationship between grain size and working strain rate and temperature during friction stir processing in AZ31 Mg alloy. Scripta Mater 51:509–514CrossRefGoogle Scholar
  42. 42.
    Ardell AJ (1985) Precipitation hardening. Metall Trans A 16:2131–2165CrossRefGoogle Scholar
  43. 43.
    Kumar N, Mishra RS, Huskamp CS, Sankaran KK (2011) Microstructure and mechanical properties of friction stir processed ultrafine grained Al-Mg-Sc sheet. Mater Sci Eng A 528:5587–5883Google Scholar
  44. 44.
    Tan JC, Tan MJ (2003) Dynamic continuous recrystallization characterization characteristics in two-stage deformation of Mg-3Al-1Zn alloy sheet. Mater Sci Eng A 339:124–132CrossRefGoogle Scholar
  45. 45.
    Mohri T, Mabuchi M, Nakamura M, Asahina T, Iwasaki H, Aizawa T, Higashi K (2000) Microstructural evolution and superplasticity of rolled Mg-9Al-1Zn. Mater Sci Eng A 290:139–144CrossRefGoogle Scholar
  46. 46.
    Higashi K, Wolfenstine J (1991) Microstructural evolution during superplastic flow of a binary Mg-8.5 wt% Li alloy. Mater Lett 10:329–332CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Fang Chai
    • 1
  • Datong Zhang
    • 1
  • Yuanyuan Li
    • 1
  • Wen Zhang
    • 1
  1. 1.National Engineering Research Centre of Near-net Shape Forming for Metallic MaterialsSouth China University of TechnologyGuangzhouPeople’s Republic of China

Personalised recommendations