Skip to main content
SpringerLink
Log in

Microstructural Investigation of VPPA–GMAW Welded 7A52 Aluminum Alloys

  • Published:
Journal of Materials Engineering and Performance Aims and scope Submit manuscript

In this study, the microstructural features of 7A52 heat-treatable aluminum alloys welded by variable polarity plasma arc (VPPA) combined with gas metal arc welding (GMAW) (VPPA–GMAW) were investigated and compared with those of 7A52 aluminum alloys welded by GMAW. The grain structures and modification of the precipitates were analyzed by optical microscopy and transmission electron microscopy. Complementary to modification of the precipitates, the precipitation evolution in the heat-affected zone and magnesium loss in the fusion zone were measured by differential scanning calorimetry and inductively coupled plasma spectroscopy. In VPPA–GMAW, the weld only needs one pass by depositing on one side of the 10-mm-thick aluminum alloy plates because of the large penetration capability of VPPA and good fluidity of the molten metal in the weld pool. Accordingly, the effect of excessive heat input on the microstructure can be minimized. The results show that the grain growth is not obvious and the magnesium loss is small in the fusion zone of VPPA–GMAW compared with that of GMAW under the condition of equal heat input to the workpiece. Small precipitates inside the grains remain homogeneously distributed, and a large volume fraction of the η′ phase exists. The VPPA–GMAW weld exhibits less tendency to soften; thus, VPPA–GMAW is appropriate for welding thick-plate aluminum alloys with a high production rate.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. S.D. Liu, Y.B. Yuan, C.B. Li, J.H. You, and X.M. Zhang, Influence of Cooling Rate After Homogenization on Microstructure and Mechanical Properties of Aluminum Alloy 7050, Met. Mater. Int., 2012, 18(4), p 679–683

    Article  CAS  Google Scholar 

  2. M. Grujicic, J.S. Snipes, R. Galgalikar, S. Ramaswami, and R. Yavari, Improved Gas Metal Arc Welding Multi-Physics Process Model and Its Application to MIL A46100 Armor-Grade Steel Butt-Welds, Multidiscip. Model. Mater. Struct., 2014, 10(2), p 176–210

    Article  Google Scholar 

  3. M. Grujicic, S. Ramaswami, J.S. Snipes, C.F. Yen, B.A. Cheeseman, and J.S. Montgomery, Multi-Physics Modeling and Simulations of MIL A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding Process, J. Mater. Eng. Perform., 2013, 22(10), p 2950–2969

    Article  CAS  Google Scholar 

  4. M. Grujicic, A. Arakere, S. Ramaswami, J.S. Snipes, R. Yavari, C.F. Yen, B.A. Cheeseman, and J.S. Montgomery, Gas Metal Arc Welding Process Modeling and Prediction of Weld Microstructure in MIL A46100 Armor-Grade Martensitic Steel, J. Mater. Eng. Perform., 2013, 22(6), p 1541–1557

    Article  CAS  Google Scholar 

  5. M. Grujicic, S. Ramaswami, J.S. Snipes, R. Yavari, A. Arakere, C.F. Yen, and B.A. Cheeseman, Computational Modeling of Microstructure Evolution in AISI1005 Steel During Gas Metal Arc Butt Welding, J. Mater. Eng. Perform, 2013, 22(5), p 1209–1222

    Article  CAS  Google Scholar 

  6. V.I. Babushok, F.C. DeLucia, J.L. Gottfried, C.A. Munson, and A.W. Miziolek, Double Pulse Laser Ablation and Plasma: Laser Induced Breakdown Spectroscopy Signal Enhancement, Spectrochim. Acta B At. Spectrosc., 2006, 61(9), p 999–1014

    Article  Google Scholar 

  7. J.Q. Su, T.W. Nelson, R. Mishra, and M. Mahoney, Microstructural Investigations of Friction Stir Welded 7050-T651 Aluminium, Acta Mater., 2003, 51(3), p 713–729

    Article  CAS  Google Scholar 

  8. W.G. Essers and A.C. Liefkens, Plasma-MIG Welding Developed by Philips, Mach. Prod. Eng., 1972, 1(11), p 632–633

    Google Scholar 

  9. K. Ono, Z.J. Liu, T. Era, T. Uezono, T. Ueyama, M. Tanaka, and K. Nakata, Development of a Plasma MIG Welding System for Aluminium, Weld. Int., 2009, 23(11), p 805–809

    Article  Google Scholar 

  10. H. Ton, Physical Properties of the Plasma-MIG Welding Arc, J. Phys. D Appl. Phys., 1975, 8(8), p 922–933

    Article  CAS  Google Scholar 

  11. H. Terasaki and S.W. Simpson, Modelling of the GMAW System in Free Flight and Short Circuiting Transfer, Sci. Technol. Weld. Joining, 2005, 10(1), p 120–124

    Article  Google Scholar 

  12. W.G. Essers and R. Walter, Heat Transfer and Penetration Mechanisms with GMA and Plasma-GMA Welding, Weld. J., 1981, 60(2), p 37–42

    Google Scholar 

  13. A.A. Resende, V.A. Ferraresi, A. Scotti, and J.C. Dutra, Influence of Welding Current in Plasma-MIG Weld Process on the Bead Weld Geometry and Wire Fusion Rate, Weld. Int., 2011, 25(12), p 910–916

    Article  Google Scholar 

  14. H.T. Hong, Y.Q. Han, M.H. Du, and J.H. Tong, Investigation on Droplet Momentum in VPPA-GMAW Hybrid Welding of Aluminum Alloys, Int. J. Adv. Manuf. Technol., 2016, 86(5–8), p 2301–2308

    Article  Google Scholar 

  15. T. Yang, H.M. Gao, S.H. Zhang, and L. Wu, Interface Behavior of Copper and Steel by Plasma-MIG Hybrid Arc Welding, Acta Metall. Sin. (Engl. Lett.), 2013, 26(3), p 328–332

    Article  CAS  Google Scholar 

  16. S.J. Chen, F. Jiang, J.L. Zhang, N. Huang, and Y.M. Zhang, Principle of Weld Formation in Variable Polarity Keyhole Plasma Arc Transverse Welding of Aluminum Alloy, Trans. China. Weld. Inst., 2013, 34(4), p 1–6

    Google Scholar 

  17. Q.L. Zhang, C.L. Fan, S.B. Lin, and C.L. Yang, Novel Soft Variable Polarity Plasma Arc and Its Influence on Keyhole in Horizontal Welding of Aluminium Alloys, Sci. Technol. Weld. Joining, 2014, 19(6), p 493–499

    Article  CAS  Google Scholar 

  18. N.J. Woodward, I.M. Richardson, and A. Thomas, Variable Polarity Plasma Arc Welding of 6.35 mm Aluminium Alloys: Parameter Development and Preliminary Analysis, Sci. Technol. Weld. Joining, 2000, 5(1), p 21–25

    Article  CAS  Google Scholar 

  19. Y.Q. Han, P. Zhao, M.H. Du, and Q.H. Yao, Numerical Simulation of Aluminum Alloys Variable Polarity Plasma Arc Welding Temperature Field, China J. Mech. Eng., 2012, 48(24), p 33–37

    Article  Google Scholar 

  20. Y.Q. Han, H.T. Hong, L. Guo, and Q.H. Yao, Vertical Welding of Aluminum Alloy During Variable Polarity Plasma Arc Welding Process with AC-DC Mixing Output Current, Trans. China Weld. Inst., 2013, 34(9), p 59–62

    Google Scholar 

  21. S.C. Wang, F. Lefebvre, J.L. Yan, I. Sinclair, and M.J. Starink, VPPA Welds of Al-2024 Alloys: Analysis and Modeling of Local Microstructure and Strength, Mater. Sci. Eng. A, 2006, 431(1–2), p 123–136

    Article  Google Scholar 

  22. G.D. Janaki Ram, T.K. Mitra, V. Shankar, and S. Sundaresan, Microstructural Refinement Through Inoculation of Type 7020 Al-Zn-Mg Alloy Welds and Its Effect on Hot Cracking and Tensile Property, J. Mater. Process. Technol., 2003, 142(1), p 174–181

    Article  CAS  Google Scholar 

  23. L.F. Mondolfo, Structure of the Aluminium: Magnesium, Zinc Alloys, Metall. Rev., 1971, 16(1), p 95–124

    Google Scholar 

  24. C.B. Fuller, M.W. Mahoney, M. Calabrese, and L. Micona, Evolution of Microstructure and Mechanical Properties in Naturally Aged 7050 and 7075 Al Friction Stir Welds, Mater. Sci. Eng. A, 2010, 527(9), p 2233–2240

    Article  Google Scholar 

  25. K. Stiller, P.J. Warren, V. Hansen, J. Angenete, and J. Gjønnes, Investigation of Precipitation in an Al-Zn-Mg Alloy After Two-Step Ageong Treatment at 100° and 150°C, Mater. Sci. Eng. A, 1999, 270(1), p 55–63

    Article  Google Scholar 

  26. X.J. Jiang, J. Tafto, B. Noble, B. Holme, and G. Waterloo, Differential Scanning Calorimetry and Electron Diffraction Investigation on Low-Temperature Aging in Al-Zn-Mg Alloys, Metall. Mater. Trans. A, 2000, 31(2), p 339–348

    Article  Google Scholar 

  27. P.N. Adler and R. Delasi, Calorimetric Studies of 7000 Series Aluminum Alloys: II. Comparison of 7075, 7050 and RX720 Alloys, Metall. Trans. A, 1977, 8(7), p 1185–1190

    Article  Google Scholar 

  28. J.L. Petty-Galis and R.D. Goolsby, Calorimetric Evaluation of the Effects of SiC Concentration on Precipitation Processes in SiC Particulate-reinforced 7091 Aluminium, J. Mater. Sci., 1989, 24(4), p 1439–1446

    Article  CAS  Google Scholar 

  29. K.V. Jata, K.K. Sankaran, and J.J. Ruschau, Friction-Stir Welding Effects on Microstructure and Fatigue of Aluminum Alloy 7050-T7451, Metall. Mater. Trans. A, 2000, 31(9), p 2181–2192

    Article  Google Scholar 

  30. X.F. Lei, D. Ying, Y.Y. Peng, Z.M. Yin, and G.F. Xu, Microstructure and Properties of TIG/FSW Welded Joints of a New Al-Zn-Mg-Sc-Zr Alloy, Met. Mater. Int., 2013, 22(9), p 2723–2729

    CAS  Google Scholar 

  31. G.F. Xu, J. Qian, D. Xiao, Y. Deng, L.Y. Lu, and Z.M. Yin, Mechanical Properties and Microstructure of TIG and FSW Joints of a New Al-Zn-Mg-Sc-Zr Alloy, Met. Mater. Int., 2016, 25(4), p 1249–1256

    CAS  Google Scholar 

  32. X.Z. Li, V. Hansen, J. Gjønnes, and L.R. Wallenberg, HREM Study and Structure Modeling of the η′ Phase, the Hardening Precipitates in Commercial Al-Zn-Mg Alloys, Acta Mater., 1999, 47(9), p 2651–2659

    Article  CAS  Google Scholar 

  33. J.K. Park and A.J. Ardell, Microstructures of the Commercial 7075 Al Alloy in the T651 and T7 Tempers, Metall. Trans. A, 1983, 14(10), p 1957–1965

    Article  Google Scholar 

  34. R.N. Shenoy and J.M. Howe, A Differential Scanning Calorimetric Study of a Weldalite Type Alloy, Scr. Metall. Mater., 1995, 33(4), p 651–656

    Article  CAS  Google Scholar 

  35. S.C. Wu, X. Yu, R.Z. Zuo, W.H. Zhang, H.L. Xie, and J.Z. Jiang, Porosity, Element Loss, and Strength Model on Softening Behavior of Hybrid Laser Arc Welded Al-Zn-Mg-Cu Alloy with Synchrotron Radiation Analysis, Weld. J., 2013, 92(3), p 64–71

    Google Scholar 

  36. P.K. Ghosh and V. Sharma, Chemical Composition and Microstructure in Pulsed MIG Welded Al-Zn-Mg Alloy, Mater. Trans., 1991, 32(2), p 145–150

    Article  CAS  Google Scholar 

  37. A. Deschamps and Y. Brechet, Influence of Predeformation and Ageing of an Al-Zn-Mg Alloy—II. Modeling of precipitation Kinetics and Yield Stress, Acta Mater., 1999, 47(1), p 293–305

    Article  CAS  Google Scholar 

  38. R. Labusch, A Statistical Theory of Solid Solution Hardening, Phys. Stat. Sol., 1970, 41(2), p 659–669

    Article  Google Scholar 

  39. J.D. Hunt, Steady State Columnar and Equiaxed Growth of Dendrites and Eutectic, Mater. Sci. Eng., 1984, 65(1), p 75–83

    Article  CAS  Google Scholar 

  40. P. Pan, J.J. Liu, and J. Ma, Influence of Welding Parameters of Pulse TIG on Weld Microstructure and Mechanical Property of Aluminum Alloys, J. Rocket Propuls., 2013, 39(1), p 52–57

    CAS  Google Scholar 

Download references

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (Grant No. 51665044). The authors would also like to acknowledge financial supports from the Science and Technology Key Programs of Inner Mongolia (Grant No. 2016-ZD08), the Natural Science Foundation of Inner Mongolia (Grant No. 2015MS0504), and the Open Project for Key Basic Research of Inner Mongolia.

Author information

Authors and Affiliations

  1. Inner Mongolia Key Laboratory of Light Metal Materials, Inner Mongolia University of Technology, Hohhot, China

    Haitao Hong, Yongquan Han, Qinghu Yao & Jiahui Tong

Authors
  1. Haitao Hong
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Yongquan Han
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Qinghu Yao
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Jiahui Tong
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Yongquan Han.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hong, H., Han, Y., Yao, Q. et al. Microstructural Investigation of VPPA–GMAW Welded 7A52 Aluminum Alloys. J. of Materi Eng and Perform 27, 5571–5580 (2018). https://doi.org/10.1007/s11665-018-3450-3

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11665-018-3450-3

Keywords

Search

Navigation