Skip to main content
Log in

Effect of heat input of TIG repair welding on microstructure and mechanical properties of cast AZ91 magnesium alloy

  • Research Paper
  • Published:
Welding in the World Aims and scope Submit manuscript

Abstract

In the present study, the effect of heat input of gas tungsten arc welding on the microstructure and mechanical properties of AZ91 magnesium alloy was investigated. The microstructural studies were performed by using an optical microscope and scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and tensile test was used to evaluate the mechanical properties. It was shown that, comparing to the base metal, a fine microstructure of α(Mg) and Mg17Al12 phase is formed in the weld metal and the size of α(Mg) phase slightly increased with heat input during welding process. The results also indicated that the thickness of partially melted zone increased with heat input. Tensile strength of welded samples was lower than that of the base metal and it decreases with increasing heat input. Failure of the welded specimens accrues in the partially melted zone. Studying of fracture surface revealed that the interface of α(Mg) and Mg17Al12 compound acts as crack initiation and growth path during the tensile test. Formation of cleavage steps in the fracture surface was the dominant fracture mechanism during tensile tests.

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

Access this article

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
Fig. 10
Fig. 11
Fig. 12
Fig. 13

Similar content being viewed by others

Data Availability

Data and materials are available.

Code availability

Not applicable.

References

  1. Munitz A, Cotler C, Stern A, Kohn G (2001) Mechanical properties and microstructure of gas tungsten arc welded magnesium AZ91D plates. Mater Sci Eng A 302:68–73

    Google Scholar 

  2. Kumar DS, Sasanka CT, Ravindra K, Suman KN (2015) Magnesium and its alloys in automotive applications–a review. J Mater Sci Technol 4:12–30

    Google Scholar 

  3. Nami B, Miresmaeili SM, Jamshidi F, Khoubrou I (2019) Effect of Ca addition on microstructure and impression creep behavior of cast AZ61 magnesium alloy. Trans Nonferrous Metals Soc China 29:2056–2065

    Google Scholar 

  4. Khomamizadeh F, Nami B, Khoshkhooei S (2005) Effect of rare-earth element additions on high-temperature mechanical properties of AZ91 magnesium alloy. Metall Mater Trans A 36:3489–3494

    Google Scholar 

  5. Tekumalla S, Gupta M (2017) An insight into ignition factors and mechanisms of magnesium based materials: a review. Mater Des 113:84–98

    Google Scholar 

  6. Adamiec J, Roskosz S, Jarosz R (2007) Repair of magnesium alloy castings by means of welding and pad welding. Mater Manuf Eng 22:21–24

    Google Scholar 

  7. Hosseini VA, Aashuri H, Kokabi A (2013) Mechanisms of joint formation throughout semisolid stir welding of AZ91 magnesium alloy. Trans Nonferrous Metals Soc China 23:2585–2590

    Google Scholar 

  8. Robson JD, Cui S, Chen ZW (2010) Incipient melting during friction stir processing of AZ91 magnesium castings. Mater Sci Eng A 527:7299–7304

    Google Scholar 

  9. Cerri E, Leo P (2014) Effect of friction stir processing on microstructure and mechanical properties of a HPDC magnesium alloy. Mater Sci Forum 783:1735–1740

    Google Scholar 

  10. Jiang J, Zhang Z (2008) The study on the plasma arc weld bonding process of magnesium alloy. J Alloys Compd 466:368–372

    Google Scholar 

  11. Wahba M, Mizutani M, Kawahito Y, Katayama S (2012) Laser welding of die-cast AZ91D magnesium alloy. Mater Des 33:569–576

    Google Scholar 

  12. Cao XJ, Jahazi M, Immarigeon JP, Wallace W (2006) A review of laser welding techniques for magnesium alloys. J Mater Process Technol 171:188–204

    Google Scholar 

  13. Watkins KG, (2003) Laser welding of magnesium alloys, in: Magnesium technology 2003, Proceedings of the Symposium held during the 2003 TMS Annual Meeting, San Diego, CA, United States, 153–156.

  14. Luo Y, Ye H, Du C, Xu H (2012) Influence of focusing thermal effect upon AZ91D magnesium alloy weld during vacuum electron beam welding. Vacuum 86:1262–1267

    Google Scholar 

  15. Luo Y, Liu J (2011) Microstructural evolution in AZ91D magnesium alloy during electron beam welding. Vacuum 85:1004–1010

    Google Scholar 

  16. Abbas M, Khan A, Ali M, Kamran MA, Azam K, Shakoor A (2014) Effect of weld current and weld speed on the micro structure and tensile properties of magnesium alloy specimens during tungsten inert gas welding, University of Engineering and Technology Taxila. Tech J 19:35

    Google Scholar 

  17. Kumar SP, Vigneshwar M, Selvamani ST, Prakash AS, Hariprasath P (2017) The comparative analysis on friction stir welded and gas tungsten arc welded AZ91 grade magnesium alloy butt joints. Mater Today Proc 4:6688–6696

    Google Scholar 

  18. Yuan T, Luo Z, Kou S (2017) Mechanism of grain refining in AZ91 Mg welds by arc oscillation. Sci Technol Weld Join 22:97–103

    Google Scholar 

  19. Yuan T, Chai X, Luo Z, Kou S (2015) Predicting susceptibility of magnesium alloys to weld-edge cracking. Acta Mater 90:242–251

    Google Scholar 

  20. Stern A, Munitz A (1999) Partially melted zone microstructural characterization from gas tungsten-arc bead on plate welds of magnesium AZ91 alloy. J Mater Sci Lett 18:853–855

    Google Scholar 

  21. Zhu T, Chen ZW, Gao W (2008) Microstructure formation in partially melted zone during gas tungsten arc welding of AZ91 Mg cast alloy. Mater Charact 59:1550–1558

    Google Scholar 

  22. Dahle AK, Lee YC, Nave MD, Schaffer PL, St John DH (2001) Development of the as-cast microstructure in magnesium–aluminium alloys. J Light Met 1:61–72

    Google Scholar 

  23. Carlone P, Palazzo GS (2015) Characterization of TIG and FSW weldings in cast ZE41A magnesium alloy. J Mater Process Technol 215:87–94

    Google Scholar 

  24. Minnick WH, Prosser MA (1996) Gas tungsten arc welding handbook. The Goodheart-Willcox Company, Tinley Park

    Google Scholar 

  25. Braszczyńska-Malik KN, Mróz M (2011) Gas-tungsten arc welding of AZ91 magnesium alloy. J Alloys Compd 509:9951–9958

    Google Scholar 

  26. Blawert C, Fechner D, Höche D, Heitmann V, Dietzel W, Kainer KU, Živanović P, Scharf C, Ditze A, Gröbner J, Schmid-Fetzer R (2010) Magnesium secondary alloys: alloy design for magnesium alloys with improved tolerance limits against impurities. Corros Sci 52:2452–2468

    Google Scholar 

  27. Nami B, Razavi H, Mirdamadi S, Shabestari SG, Miresmaeili SM (2010) Effect of Ca and rare earth elements on impression creep properties of AZ91 magnesium alloy. Metall Mater Trans A 41:1973–1982

    Google Scholar 

  28. Nami B, Shabestari SG, Razavi H, Mirdamadi S, Miresmaeili SM (2011) Effect of Ca, RE elements and semi-solid processing on the microstructure and creep properties of AZ91 alloy. Mater Sci Eng A 528:1261–1267

    Google Scholar 

  29. Khoubrou I, Nami B, Miresmaeili SM (2020) Investigation on the creep behavior of AZ91 magnesium alloy processed by severe plastic deformation. Met Mater Int 26:196–204

    Google Scholar 

  30. Kou S (1987) Welding metallurgy. Cambridge Univ Press, Cambridge

    Google Scholar 

  31. Nave MD, Dahle AK, StJohn DH (2000) Eutectic growth morphologies in magnesium-aluminium alloys. Magnes Technol 1:233–242

    Google Scholar 

  32. Zhu T, Chen ZW, Gao W (2006) Incipient melting in partially melted zone during arc welding of AZ91D magnesium alloy. Mater Sci Eng A 416:246–252

    Google Scholar 

  33. Zhu TP, Chen ZW, Gao W (2007) Partial melting and re-solidification in partially melted zone during gas tungsten arc welding of AZ91 cast alloy. Trans Nonferrous Metals Soc China 17:342–346

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Bahram Nami.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Recommended for publication by Commission XV - Design Analysis and Fabrication of Welded Structures

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Assar, A., Nami, B., Arab, N.B.M. et al. Effect of heat input of TIG repair welding on microstructure and mechanical properties of cast AZ91 magnesium alloy. Weld World 65, 1131–1143 (2021). https://doi.org/10.1007/s40194-021-01100-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s40194-021-01100-8

Keywords

Navigation