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利用金相显微镜(OM)、X射线衍射(XRD)、扫描电镜(SEM)和高温拉伸对挤压态ZM61-x Sn(x=2,4,8,质量分数,%)合金的显微组织、高温力学性能和断裂机制进行了研究。结果表明添加Sn元素可有效细化合金组织且细化效果随Sn含量的增加而增强。挤压态ZM61-x Sn(x=2,4,8)合金的平均晶粒尺寸分别为11,8和4μm。随Sn含量的增加,合金的力学性能先升高后降低。在所有的实验合金中ZM61-4Sn合金的强度最高,当在180℃下进行拉伸实验时,其极限抗拉强度和屈服强度分别为216和173 MPa。合金的延伸率随Sn含量的增加而增加,当拉伸温度为300℃时,ZM61-x Sn(x=2,4,8)合金的延伸率分别为183.8%,235.8%和258.6%。ZM61-4Sn合金具有最好的强度和塑性的结合。试样最后的断裂主要由局部缩颈引起以及试样的主要断裂机制为显微孔洞聚集。当在260和300℃下拉伸时,合金发生了不完全的动态再结晶。
Microstructure of extruded ZM61-xSn (x = 2, 4, 8, mass fraction,%) microstructure was characterized by OM, XRD, SEM and high temperature tensile Tissue, high temperature mechanical properties and fracture mechanism were studied. The results show that the addition of Sn element can effectively refine the alloy structure and the refining effect increases with the increase of Sn content. The average grain sizes of the as-extruded ZM61-xSn (x = 2,4,8) alloys were 11, 8 and 4 μm, respectively. With the increase of Sn content, the mechanical properties of the alloy first increased and then decreased. The ZM61-4Sn alloy has the highest strength in all the experimental alloys. The ultimate tensile strength and yield strength of the ZM61-4Sn alloy are 216 and 173 MPa, respectively, at 180 ℃. The elongation of the alloy increases with the increase of Sn content. The elongation of ZM61-x Sn (x = 2, 4, 8) alloy is 183.8%, 235.8% and 258.6% when the stretching temperature is 300 ℃. ZM61-4Sn alloy with the best combination of strength and plasticity. The final fracture of the specimen is mainly caused by the local constriction and the main fracture mechanism of the specimen is micropore aggregation. When stretched at 260 and 300 ° C, the alloy underwent incomplete dynamic recrystallization.