Effects of Mn on Microstructure and Mechanical Properties of Mg-2Sn Magnesium Alloys
We researched on the mechanism of trace Mn improving the mechanical properties of Mg-2 Sn as-cast and ex-truded alloys.By using casting and hot extrusion methods,we added 0.3%,0.5% and 1.0%Mn to Mg-2 Sn magnesium alloy,two kinds of alloy,namely as cast and extruded,were obtained.The mechanical properties were studied by electronic universal material testing machine.The microstructures were studied by optical microscope(OM),scanning electron mi-croscope(SEM)and X-ray diffraction(XRD)and electron backscatter diffraction(EBSD).As the Mn content increased from 0.3%to 1.0%,the second phase in the cast alloy shifted from Mg2 Sn phase to Mg2 Sn phase and α-Mn coexist trans-formation.The transformation of the second phase significantly improved the yield and tensile strength of the cast alloy with little change in elongation.When the Mn content was 0.5%,its comprehensive performance was the best with a tensile strength of 210.3 MPa,a yield strength of 117.5 MPa,and an elongation of 12.2%.The strength of the extruded alloy in-creased with the increase of Mn content,while the elongation showed an opposite trend.This may be related to the forma-tion of higher dislocations in alloys with high Mn content,the extruded Mg-2 Sn-0.5 Mn alloy had the best comprehensive mechanical properties with a tensile strength of 240.4 MPa,a yield strength of 186.4 MPa,and an elongation of 13.1%.Trace Mn could significantly improve the tensile and yield strength of cast and extruded alloys,and the comprehensive per-formance of Mg-2 Sn-0.5 Mn was the best.
microalloyingMg-2 Sn series magnesium alloyas-cast stateextruded statemechanical propertiesmi-crostructure