| Pure magnesium has good damping properties, but poor mechanical properties, generally not used directly. Alloying can improve its mechanical properties, but significantly reduces the damping performance, resolve conflicts mechanical properties and damping properties, good research and development of the integrated properties of magnesium alloy of tin is necessary. In this paper, through the cast tin binary alloy magnesium damping properties of seven different components Mg-(1,2,3,4,5,7,10) wt% Sn and other analysis explores the damping Mg-Sn alloy mechanism. Find the binary Mg-Sn alloy damping performance as the best Mg-2Sn, and then add a third alloying element Co and Zr, analyze their impact on performance and mechanical properties of Mg-Sn alloy (SMA); and on Seven two yuan cast alloy hot extrusion process, in order to obtain excellent mechanical properties of high damping Mg-Sn alloy.Through analysis:(1) the damping mechanism of Mg-Sn alloy was combined with the dislocation interaction damping and phase boundary damping. The phase boundary damping was from the eutectic phase (Mg?Sn and α-Mg) that caused interfacial friction damping. At high strain level, Q"1 factor values for Mg-(1-5 wt%) Sn were increased in turn:T4> F> T6, which indicated the damping mechanism was dominated by dislocation; for Mg-(7-10 wt%), the values of damping factor Q-1 were increased in turn:F> T4> T6, which indicated that interfacial friction damping played the dominant effect.(2) Mg-2Sn Co alloy was added after the grain has been refined, and the formation of a new secondary phases Mg2Co, increasing the Co content in the alloy, which precipitates (Mg2Sn+Mg2Co) increased eutectic (a-Mg+Mg2Sn) distributed decline continuity. Compared to several other ternary alloy, Mg-2Sn-lCo Alloy Structure ideal, which precipitates regardless of the size or shape are more evenly distributed. After the alloy is added Co. damping properties have a certain degree of reduction, in which the damping properties of Mg-2Sn-lCo best alloy and analysis may be in common phase boundary dislocation damping effect of damping. Zr is added to improve the damping properties of Mg-2Sn alloys, because Zr is Zr fine particle precipitation in the grains. Zr dots and dislocation interactions lead to improved damping properties of the alloy.(3) Mg-xSn after squeezing small homogeneous equiaxed grain dispersed within there Mg2Sn phase, and with the increase of x, the smaller the grain size, volume and number of increase in α-Mg matrix phase MgaSn large, extruded alloy grains will break, so-extruded Mg-Sn alloy fine grain size; Mg-Sn alloy damping mechanism is not just for the dislocation damping mechanism, and grain boundary damping influence, especially extrusion state Mg-xSn (x= 4,5,7,10wt.%) alloy at lower strain amplitude, phase boundaries play a significant damping. Mg-Sn alloy extruded state damping properties than cast Mg-Sn alloy low, but at a greater impact when the grain boundary damping damping-extruded Mg-Sn alloy than cast alloy extrusion damping herein after the Mg-Sn alloys have reached 0.04, which are all high damping alloy; squeeze the grain crusher, dynamic recrystallization, grain refinement, it is extruded state strength Mg-Sn alloy than cast alloy, Sn added to pure magnesium in solid solution strengthening and grain refinement effect, while the hard phase formed Mg2Sn can also increase the strength of the matrix, Mg-xSn alloy, the bigger x is, the higher its strength. |
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