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.
关键词
微合金化/Mg-2Sn系镁合金/铸态/挤压态/力学性能/微观组织
Key words
microalloying/Mg-2 Sn series magnesium alloy/as-cast state/extruded state/mechanical properties/mi-crostructure
维普
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