Microstructures, mechanical properties and compressive creep behaviors of as-cast Mg-5%Sn-(0–1.0)%Pb alloys

Abstract

The microstructures, tensile properties and compressive creep behaviors of Mg-5%Sn-(0–1.0)%Pb (mass fraction) alloys were studied. The microstructures of the Mg-Sn-Pb alloys consist of dendritic α-Mg and Mg₂Sn phase. The addition of Pb can refine the size of Mg₂Sn phase and grain size, reduce the amount of Mg₂Sn phase at grain or inter-dendrite boundaries and change the distribution of Mg₂Sn phase. Pb exists in the Mg₂Sn phase or dissolves in α-Mg matrix. The mechanical properties of the tested alloys at room temperature are improved with the addition of Pb. When the Pb content is over 0.5%, the mechanical properties are decreased gradually. The Mg-5%Sn-0.5%Pb shows the best ultimate tensile strength and elongation, 174 MPa and 14.3%, respectively. However, the compressive creep resistance of the Mg-Sn-Pb alloys is much lower than that of the Mg-Sn binary alloy at 175 °C with applied load of 55 MPa, which means that Pb has negative effects on the compressive creep resistance of the as-cast Mg-Sn alloys.

Keywords

Mg-Sn-Pb alloy / microstructures / mechanical properties / compressive creep / Mg₂Sn phase

References

[1] MordikeB. L., EbertT.. Magnesium: Properties—application—potential [J]. Materials Science and Engineering A, 2001, 302: 37-45

[2] MassalskiT. B., OkamotoH.Binary alloy phase diagrams [M], 1990, Ohio, ASM International, Materials Park

[3] LiuH.-m., ChenY.-g., TangY.-b., WeiS.-h., NiuGao.. The microstructure, tensile properties, and creep behavior of as-cast Mg-(1–10)%Sn alloys [J]. Journal of Alloys and Compounds, 2007, 440: 122-126

[4] WuW.-h., XiaC.-qing.. Microstructures and mechanical properties of Mg-Ce-Zn-Zr wrought alloy [J]. Journal of Central South University, 2004, 11(4): 19-23

[5] LiuH.-m., ChenY.-g., TangY.-b., HuangD.-m., NiuGao.. The microstructure and mechanical properties of permanent-mould cast Mg-5wt%Sn-(0–2.6)wt%Di alloys [J]. Materials Science and Engineering A, 2006, 437: 348-355

[6] ZhangX.-p., ChenY.-g., XiaoS.-f., TangY.-b., NiuG., WeiS.-h., ZhaoY.-hua.. Microstructure, tensile properties and compressive creep resistance of Mg-(5–8.5)%Sn-2%La alloys [J]. Transactions of Nonferrous Metals Society of China, 2008, 18: s229-s305

[7] LiuH.-m., ChenY.-g., TangY.-b., WeiS.-h., NiuGao.. Tensile and indentation creep behavior of Mg-5%Sn and Mg-5%Sn-2%Di alloys [J]. Materials Science and Engineering A, 2007, 464: 124-128

[8] WeiS.-h., ChenY.-g., TangY.-b., ZhangX.-p., LiuM., XiaoS.-f., ZhaoY.-hua.. Compressive creep behavior of Mg-Sn-La alloys [J]. Materials Science and Engineering A, 2009, 508: 59-63

[9] JianW.-w., KangZ.-x., LiY.-yuan.. Effect of hot plastic deformation on microstructure and mechanical property of Mg-Mn-Ce magnesium alloy [J]. Transactions of Nonferrous Metals Society of China, 2007, 17: 1158-1163

[10] LimH. K., KimD. H., LeeJ. Y., KimW. T., KimD. H.. Effects of alloying elements on microstructures and mechanical properties of wrought Mg-MM-Sn alloy [J]. Journal of Alloys and Compounds, 2009, 468: 308-314

[11] YuK., LiW.-x., WangR.-chu.. Mechanical properties and microstructure of as-cast and extruded Mg-(Ce, Nd)-Zn-Zr alloys [J]. Journal of Central South University, 2005, 12(5): 36-40

[12] CandanS., UnalM., TurkmenM., KocE., TurenY., CandanE.. Improvement of mechanical and corrosion properties of magnesium alloy by lead addition [J]. Materials Science and Engineering A, 2009, 501: 115-118

[13] BalasubramaniN., SrinivasanA., PillaiU. T. S., PaiB. C.. Effect of Pb and Sb additions on the precipitation kinetics of AZ91 magnesium alloy [J]. Materials Science and Engineering A, 2007, 457: 275-281

[14] SrinivasanA., PillaiU. T. S., PaiB. C.. Effect of Pb addition on ageing behavior of AZ91 magnesium alloy [J]. Materials Science and Engineering A, 2007, 452/453: 87-92

[15] LUO A. Understanding the solidification of magnesium alloys [C]// Proceedings of the Third International Magnesium Conference, Manchester, UK, 1996: 449–464.

[16] KashyapK. T., RamachandraC., SujathaM., ChatterjiB.. Role of diffusional coherency strain theory in the discontinuous precipitation in Mg-Al alloy [J]. Bulletin of Materials Science, 2000, 23: 39-45