Effects of Mn Content on Microstructure and Hardness of 6061 Aluminum Alloy

  • Xingyu Ding
  • Yongqi Cheng
  • Peng Zhang
  • Yong Dong
  • Zhengrong Yao
  • Peisong Jiang
Conference paper


Microalloying is an effective way to improve material properties. By means of scanning electron microscope/energy spectrum, X-ray diffraction, metallographic analysis and hardness tests, the effects of microalloying element Mn on as-cast, homogenization, aging microstructure and hardness were investigated in the basic of 6061 aluminum alloy. The results showed that the as-cast 6061 alloy consisted of the primary Al, the irregular strip-shaped Al8(FeMn)2Si phases, fishbone-shaped Al5(FeMn)Si phases and Mg2Si phases. Through microalloying, the morphology of phases transformed from irregular strip into fishbone obviously as Mn content increased. After homogenization process, Mg2Si phase dissolved into the alloy matrix but iron-rich phase cannot. With the increase of Mn content, the phase transformation of fishbone-shaped Al5(FeMn)Si to particle-shaped Al8(FeMn)2Si occurred. During solution-aging treatment, higher Mn content could promote the precipitation of stable phase β(Mg2Si). Mn had a significant effect on the morphology of the crystalline phases which had a direct influence on the hardness of aluminum alloy. It was found that the addition of 0.24 wt% Mn to 6061 aluminum alloy could make the as-cast and aging alloys achieve the maximum hardness value 67 and 105 HBW, respectively.


6061 aluminum alloy Constituent Hardness Mn 



This research was supported by the National Natural Science Foundation of China (51205065), Guangdong special fund for public welfare research and capacity building (2016A010103032), and Guangdong applied science and technology research and development special fund project (2015B090926006), innovative training program for college students (201611845025).


  1. 1.
    D. Masionnette, M. Suery, D. Nelias, P. Chaudet, T. Epicier, Effects of heat treatments on the microstructure and mechanical properties of a 6061 aluminium alloy, Mater. Sci. Eng. A. 528(6) (2011) 2718.Google Scholar
  2. 2.
    P. Du, X.D. Yan, Y.L. Li, et al, Transformation mechanism of iro-rich phase in 6061 aluminum alloy during homogenization Trans, Nonferrous Met. Soc. China. 21(5) (2011) 981–987.Google Scholar
  3. 3.
    S. Seifeddine, I.L. Svensson, Predicition of mechanical properties of cast aluminum components at various iron contents, Materials & Design. 31 (Supplement), 6 (2010).Google Scholar
  4. 4.
    L.Z. He, Microstructure and Mechanical of Al-Mg-Si alloys, Northeastern University. 2001.Google Scholar
  5. 5.
    L. Lodgaard, N. Ryum, Precipitation of dispersoids containing Mn and/or Cr in Al-Mg-Si alloys, Mater. Sci. Eng. A. 283(1–2) (2000) 144.Google Scholar
  6. 6.
    W. Eidhed, H. Tezuka, T. Sato, Effects of Cr and Cr/Mn combined additions on semi-solid microstructures of Al-Mg-Si alloys producedby D-SSF process, J. Mater. Sci. Technol. 24(1) (2008) 21.Google Scholar
  7. 7.
    H. Li, Z.X. Shi, Z.X. Wang, et al, Effects of Mn and Cr on microstructure and properties of Al-Mg-Si-Cu alloys, T. Mater. Heat. Tera. (10) 2011 100–105.Google Scholar
  8. 8.
    L.H. Xu, Z.L. Tian, Y. Peng, et al, Effects of minor elements on weld structure and mechanical properties of high strength aluminum alloy, Nonferrous Met. Soc. China. 18(6) (2008) 959–966.Google Scholar
  9. 9.
    H. Liu, Y.H. Liu, G. Zhao, C.M. Liu, L. Zuo, Effect of Mn on constituents of Al-Mg-Si-Cu alloys, Nonferrous Met. Soc. China. 14(11) (2004) 1906.Google Scholar
  10. 10.
    L.Z. He, Y.B. Chen, J.Z. Cui, Effect of homogenization on microstructure and property of Al-Mg-Si-Cu alloys, Rare Met. Mater. Eng. 37(9) (2008) 1635.Google Scholar
  11. 11.
    X.D Wang, Effects of Mn on microstructure of Mg-containing high-silicon aluminum alloy, Northeastern University. 2014.Google Scholar
  12. 12.
    C. Ravi, C. Wolverton, First- principles study of crystal structure and stability of Al-Mg-Si-(Cu) precipitates, Acta Mater. 52(14) (2004) 4213.Google Scholar
  13. 13.
    D.S. Park, S.W. Nam, Effects of manganese dispersoid on the mechanical properties in Al-Zn-Mg alloys, J. Mater. Sci. Technol. 30(5) (1995) 1313.Google Scholar
  14. 14.
    L.Z. HE, Y.B. Chen, J.Z. Cui, et al, Effects of Mn and Zr on microstructure and properties of new Al-Mn-Si-Cu alloy, Rare Met. Mater. Eng. 33(12) (2004) 1337.Google Scholar
  15. 15.
    X.M. Zhang, B. Ke, J.G. Tang, et al, Effects of Mn Content on Microstructure and Mechanical Properties of 6061 Aluminum Alloy. Chin J. Mater. Res. (04) (2013) 337–341.Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • Xingyu Ding
    • 1
  • Yongqi Cheng
    • 1
  • Peng Zhang
    • 1
  • Yong Dong
    • 1
  • Zhengrong Yao
    • 1
  • Peisong Jiang
    • 1
  1. 1.Faculty of Material and Energy EngineeringGuangdong University of TechnologyGuangzhouChina

Personalised recommendations