Influence of Zr and Mn additions on microstructure and properties of Mg—2.5wt%Cu—Xwt%Zn (X = 2.5, 5 and 6.5) alloys

Abstract

This work studied the effects of adding Zr and Mn in amounts less than 1wt% on the microstructure, mechanical properties, casting properties, and corrosion resistance of Mg—Zn—Cu alloys containing 2.5wt% Cu and 2.5wt%—6.5wt% Zn. The hardness and electrical conductivity measurements were used to find an optimal heat treatment schedule with the best mechanical properties. It has been established that Zr significantly increases the yield strength of the alloys due to a strong grain refinement effect. However, the presence of Mn and Zr has a detrimental effect on alloy’s elongation at fracture. It was shown that the precipitation of the Mg₂Cu cathodic phase in the alloy structure negatively affects the corrosion behavior. Nevertheless, the addition of Mn decreases the corrosion rate of the investigated alloys. The best combination of the mechanical, casting, and corrosion properties were achieved in the alloys containing 2.5wt% Cu and 5wt% Zn. However, the Mn or Zr addition can improve the properties of the alloys; for example, the addition of Mn or Zr increases the fluidity of the alloys.

Keywords

magnesium alloy / Mg—Zn—Cu / casting alloy / Mn addition / Zr addition

References

[1] Kainer KU. Magnesium Alloys and Their Applications, 2000, Weinheim, Wiley-VCH Verlag GmbH

[2] Luo AA. Magnesium casting technology for structural applications. J. Magnes. Alloys, 2013, 1(1): 2.

[3] Pan HC, Ren YP, Fu H, Zhao H, Wang LQ, Meng XY, Qin GW. Recent developments in rare-earth free wrought magnesium alloys having high strength: A review. J. Alloys Compd., 2016, 663, 321.

[4] You SH, Huang YD, Kainer KU, Hort N. Recent research and developments on wrought magnesium alloys. J. Magnes. Alloys, 2017, 5(3): 239.

[5] Yu H, Kim YM, You BS, Yu HS, Park SH. Effects of cerium addition on the microstructure, mechanical properties and hot workability of ZK60 alloy. Mater. Sci. Eng. A, 2013, 559, 798.

[6] Chen XH, Liu LZ, Pan FS, Mao JJ, Xu XY, Yan T. Microstructure, electromagnetic shielding effectiveness and mechanical properties of Mg-Zn-Cu-Zr alloys. Mater. Sci. Eng. B, 2015, 197, 67.

[7] Zhang Y, Huang XF, Ma Y, Chen TJ, Li YD, Hao Y. Effects of Cu addition on microstructure and mechanical properties of as-cast Mg-6Zn magnesium alloy. China Foundry, 2017, 14(4): 251.

[8] Mordike BL, Ebert T. Magnesium: Properties—applications—potential. Mater. Sci. Eng. A, 2001, 302(1): 37.

[9] Buha J. Mechanical properties of naturally aged Mg-Zn-Cu-Mn alloy. Mater. Sci. Eng. A, 2008, 489(1–2): 127.

[10] Xu LG, Li XX, Ye J, Ji X, Qiu H, Luo J, Yang HG. Thermodynamic optimization design of casting Mg-Zn-Cu alloy. Adv. Mater. Res., 2014, 852, 183.

[11] Polmear IJ. Light Alloys: From Traditional Alloys to Nanocrystals, 2005, 4th ed. Oxford, Butterworth-Heinemann

[12] Avedesian MM, Baker H. Magnesium and Magnesium Alloys, 1999, Materials Park, OH, ASM Specialty Handbook, ASM International

[13] Song YW, Han EH, Shan DY, Yim CD, You BS. The effect of Zn concentration on the corrosion behavior of Mg—xZn alloys. Corros. Sci., 2012, 65, 322.

[14] C. Liu, X.K. Fu, H.B. Pan, P. Wan, L. Wang, L.L. Tan, K.H. Wang, Y. Zhao, K. Yang, and P.K. Chu, Biodegradable Mg-Cu alloys with enhanced osteogenesis, angiogenesis, and long-lasting antibacterial effects, Sci. Rep., 6(2016), art. No. 27374.

[15] Makar GL, Kruger J. Corrosion of magnesium. Int. Mater. Rev., 1993, 38(3): 138.

[16] Song GL. Control of biodegradation of biocompatable magnesium alloys. Corros. Sci., 2007, 49(4): 1696.

[17] Lunder O, Aune TK, Nisancioglu K. Effect of Mn additions on the corrosion behavior of mould-cast magnesium ASTM AZ91. Corrosion, 1987, 43(5): 291.

[18] Gusieva K, Davies CHJ, Scully JR, Birbilis N. Corrosion of magnesium alloys: The role of alloying. Int. Mater. Rev., 2015, 60(3): 169.

[19] Zhu HM, Luo CP, Liu JW, Jiao DL. Effects of Cu addition on microstructure and mechanical properties of as-cast magnesium alloy ZK60. Trans. Nonferrous Met. Soc. China, 2014, 24(3): 605.

[20] Gandel DS, Easton MA, Gibson MA, Abbott T, Birbilis N. The influence of zirconium additions on the corrosion of magnesium. Corros. Sci., 2014, 81, 27.

[21] Andersson JO, Helander T, Höglund L, Shi PF, Sundman B. Thermo-Calc & DICTRA, computational tools for materials science. Calphad, 2002, 26(2): 273.

[22] Thermo-Calc Software, TCMG4 Magnesium Alloys Databases Version 4, Thermo-Calc Software, Stockholm [2020-01-10]. https://thermocalc.com/products/databases/magnesium-based-alloys/

[23] Koltygin AV, Bazhenov VE, Letyagin NV, Belov VD. The influence of composition and heat treatment on the phase composition and mechanical properties of ML19 magnesium alloy. Russ. J. Non-Ferrous Met., 2018, 59(1): 32.

[24] Bazhenov VE, Petrova AV, Koltygin AV. Simulation of fluidity and misrun prediction for the casting of 356.0 aluminum alloy into sand molds. Int. J. Metalcast., 2018, 12(3): 514.

[25] Koltygin AV, Bazhenov VE, Belova EA, Nikitina AA. Development of a magnesium alloy with good casting characteristics on the basis of Mg-Al-Ca-Mn system, having Mg-Al₂Ca structure. J. Magnes. Alloys, 2013, 1(3): 224.

[26] ASTM International ASTM Standard G102-89. Standard Practice for Calculation of Corrosion Rates and Related Information from Electrochemical Measurements, 2015, West Conshohocken, ASTM International

[27] Qian M, StJohn DH, Frost MT. Characteristic zirconium-rich coring structures in Mg-Zr alloys. Scripta Mater., 2002, 46(9): 649.

[28] Yang L, Zhou XR, Curioni M, Pawar S, Liu H, Fan ZY, Scamans G, Thompson G. Corrosion behavior of pure magnesium with low iron content in 3.5 wt% NaCl solution. J. Electrochem. Soc., 2015, 162(7): C362.

[29] Gjønnes J, Simensen CJ. An electron microscope investigation of the microstructure in an aluminium-zinc-magnesium alloy. Acta Metall., 1970, 18(8): 881.

[30] Song GA, Lee JS, Park JS, Lee NS, Lee WH, Kim KB. Mechanical properties of large-scale Mg-Cu-Zn ultrafine eutectic composites. J. Alloys Compd., 2009, 481(1–2): 135.

[31] Buha J, Ohkubo T. Natural aging in Mg-Zn(-Cu) alloys. Metall. Mater. Trans. A, 2008, 39(9): 2259.

[32] Robson JD, Henry DT, Davis B. Particle effects on recrystallization in magnesium-manganese alloys: Particle pinning. Mater. Sci. Eng. A, 2011, 528(12): 4239.

[33] Peng GS, Wang Y, Fan Z. Competitive heterogeneous nucleation between Zr and MgO particles in commercial purity magnesium. Metall. Mater. Trans. A, 2018, 49(6): 2182.

[34] Bazhenov VE, Koltygin AV, Sung MC, Park SH, Tselovalnik YV, Stepashkin AA, Rizhsky AA, Belov MV, Belov VD, Malyutin KV. Development of Mg-Zn-Y-Zr casting magnesium alloy with high thermal conductivity. J. Magnes. Alloys, 2021, 9(5): 1567.

[35] ASM Handbook Committee. Properties and Selection: Nonferrous Alloys and Special-Purpose Materials. ASM Handbook, Vol. 2, 1990, Materials Park, OH, ASM International

[36] Qian M, Das A. Grain refinement of magnesium alloys by zirconium: Formation of equiaxed grains. Scripta Mater., 2006, 54(5): 881.

[37] Vinotha D, Raghukandan K, Pillai UTS, Pai BC. Grain refining mechanisms in magnesium alloys—An overview. Trans. Indian Inst. Met., 2009, 62(6): 521.

[38] Lee YC, Dahle AK, StJohn DH. The role of solute in grain refinement of magnesium. Metall. Mater. Trans. A, 2000, 31(11): 2895.

[39] Lloyd DJ, Court SA. Influence of grain size on tensile properties of Al-Mg alloys. Mater. Sci. Technol., 2003, 19(10): 1349.

[40] Dahle AK, Tøndel PA, Paradies CJ, Arnberg L. Effect of grain refinement on the fluidity of two commercial Al-Si foundry alloys. Metall. Mater. Trans. A, 1996, 27(8): 2305.

[41] Ravi KR, Pillai RM, Amaranathan KR, Pai BC, Chakraborty M. Fluidity of aluminum alloys and composites: A review. J. Alloys Compd., 2008, 456(1–2): 201.

[42] Li HX, Qin SK, Ma YZ, Wang J, Liu YJ, Zhang JS. Effects of Zn content on the microstructure and the mechanical and corrosion properties of as-cast low-alloyed Mg-Zn-Ca alloys. Int. J. Miner. Metall. Mater., 2018, 25(7): 800.

[43] Wang PJ, Ma LW, Cheng XQ, Li XG. Influence of grain refinement on the corrosion behavior of metallic materials: A review. Int. J. Miner. Metall. Mater., 2021, 28(7): 1112.