Abstract
These experiments were done to evaluate the feasibility of locally modifying the surface properties of magnesium alloys with friction-stir processing. The magnesium alloy used for the study was high-pressure die-cast AM60B, nominally Mg−6Al−0.13 Mn (wt.%). Friction-stir passes were made with a translation speed of 1.7 mm/s using tool-rotation speeds of 1,250 rpm or 2,500 rpm. Stir passes with good appearance were obtained under both conditions. In some cases up to five passes were overlapped on a single bar to produce stir zones with cross-sectional dimensions of about 1.5 mm×10 mm. Metallographic examinations indicated that the stir zones were largely comprised of a magnesium solid solution with equiaxed grains on the order of 5–10 μm in size. Hardness mapping showed that the stir zones experienced increases of 16–25% compared to the as-cast metal. Room-temperature testing showed that, compared to the cast metal, the stir zones had flow stresses nearly 20% higher with about twice the tensile elongation.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
International Magnesium Association, www.intimag. org/statistics.aspx.
K. Johnson, “Magnesium Automotive Applications”, Advanced Materials and Processes 160 (6) (2002), pp. 62–65.
H. Zhao and T. DebRoy, “Pore Formation during Laser Beam Welding of Die-Cast Magnesium Alloy AM60B—Mechanism and Remedy”, Welding Journal, 80 (2001), pp. 204-s–210-s.
A.K. Dasgupta and J. Mazumder, “Laser Welding of AM60 Magnesium Alloy”, Magnesium Technology 2004, ed. A.A. Luo (Warrendale, PA: TMS, 2004), pp 43–48.
N. Li et al. “Friction Stir Welding of Magnesium AM60 Alloy”, Magnesium Technology 2004, ed. A.A. Luo (Warrendale, PA: TMS, 2004), pp. 19–23.
J.I. Skar et al. “Friction Stir Welding of Magnesium Die Castings,” Magnesium Technology 2004, ed. A.A. Luo (Warrendale, PA: TMS, 2004), pp. 25–30.
T.E. Pipel, “Magnesium Heliarc Welding” Welding Journal, 21 (1942), pp. 770–772.
F.A. Wassell, “Helium-Shielded Arc Welding of Magnesium Alloys”, Welding Journal, 23 (1944), pp. 148–152.
L.F. Pearsall “Magnesium Welding”, Welding Journal, 25 (1946), p. 549.
P. Klain, “Inert-Gas-Shielded Metal-Arc Welding of Magnesium”, Welding Journal, 30 (1951) pp. 887–893.
P. Klain, “The Welding of Magnesium Alloys,” Welding Journal 36 (1957) pp. 321-s–329-s.
A. Weisheit, R. Gallun, and B.L. Mordike, “CO2 Laser Beam Welding of Magnesium-Based Alloys,” Welding Journal, 77 (1998) pp. 149-s–154-s.
K. Kato and H. Tokisue, “Friction Welding of Magnesium Alloys”, Welding International, 8 (1994) pp. 12–17.
J.A. Esparza et al., “Friction Stir Welding of Magnesium Alloy AZ31B,” Journal of Materials Science, 21 (2002) pp. 917–920.
A. Munitz et al., “GTA and EB Welding of AM50 and AZ31 Cast Magnesium Alloys: Microstructure and Mechanical Properties” Trends in Welding Research: Proceedings of the 6th International Conference (Materials Park, OH: ASM International, 2003), pp. 754–759.
U. Draugelates et al., “Properties of Non Vacuum Electron Beam Welds of Magnesium Alloys,” Magnesium Alloys and Their Applications (Frankfurt, Germany: Werkstoff-Informationsgesellschaft mBH, 1998), pp 601–606.
W.F. Hess et al., “Optimum Welding Conditions and General Characteristics of Spot Welds in Magnesium Alloy Sheet,” Welding Journal, 26 (1947) pp. 268-s–282-s.
L. Liu, J. Wang, and G. Song, “Hybrid Laser-TIG Welding, Laser Beam Welding and Gas Tungsten Arc Welding of AZ31B Magnesium Alloy,” Materials Science and Engineering A 381 (2004), pp. 129–133.
A.V. Antonov et al. “Special Features of Electroslag Welding of VMD-3 Magnesium Alloy,” Paton Welding Journal, 1 (1989), pp. 339–340.
Metals Handbook Desk Edition, Second Edition, ed. Joseph R. Davis (Materials Park, OH: ASM International, 1998).
International Magnesium Association, www. intimag.org/statistics.aspx.
H. Zhao and T. DebRoy, “Pore Formation during Laser Beam Welding of Die-Cast Magnesium Alloy AM60B—Mechanism and Remedy,” Welding Journal, 80 (2001), pp. 204-s–210-s.
R. Johnson, “Friction Stir Welding of Magnesium Alloys,” Materials Science Forum, 419–422 (2003), pp. 365–370.
J.B. Clark, “Age Hardening in a Mg-9 wt% Al Alloy,” Acta Metallurgica, 16 (1968), pp. 141–152.
J.A. Esparza, W.C. Davis, and L.E. Murr, “Microstructure-Property Studies in Friction-Stir Welded, Thixomolded Magnesium Alloy AM60,” Journal of Materials Science, 38 (2003), pp. 941–952.
N. Saunders, “Mg-DATA, a Database for Thermodynamic Calculations for Mg Alloys,” (Surrey, United Kingdom: Thermotech Ltd.).
J.P. Weiler et al., “Relationship between Internal Porosity and Fracture Strength of Die-Cast Magnesium AM60B Alloy,” Materials Science and Engineering A, 395 (2005), pp. 315–322.
Author information
Authors and Affiliations
Additional information
Author's Note: This manuscript has been authored by a contractor of the U.S. government under contract DE-AC05-00OR22725. Accordingly, the U.S. government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. government purposes.
Rights and permissions
About this article
Cite this article
Santella, M., Frederick, A., Degen, C. et al. The use of friction-stir technology to modify the surfaces of AM60B magnesium die castings. JOM 58, 56–61 (2006). https://doi.org/10.1007/s11837-006-0025-9
Issue Date:
DOI: https://doi.org/10.1007/s11837-006-0025-9