Y对Mg-Zn合金组织和力学性能的影响

Effects of Yttrium on Microstructure and Mechanical Properties of Mg-Zn Alloys

在7.5kW的坩埚电阻炉中制备了Y质量分数分别为1.5%、3.0%、6.0%的3种Mg-3Zn合金试样,分析讨论了Y在合金中的存在形式和作用机制。随着Y含量的提高,合金的二次相由I相+W相过渡到W相+H相,合金的组织结构有粗化的趋势,晶间组织的形态也由细线状向网状转变。测试了合金的力学性能,结果发现,当Y含量从1.5%提高到3.0%时,合金的屈服强度、冲击韧度和硬度分别提高了56.6%、7.6%和27.4%,而伸长率降低了11.8%。但当Y含量达到6.0%时,合金的屈服强度和硬度仍有所提高,但冲击韧度却有所下降。

Mg-3Zn magnesium alloys with 1.5%, 3.0% and 6.0% Y addition were prepared in crucible furnace with 7.5 kW. Effects of Y addition on microstructure and properties of Mg-3Zn alloy have been described. With increasing in Y addition, the secondary phase in the alloy is transformed from I phase +W phase into W phase +H phase, and the microstructure of the alloy gradually becomes coarse, in which the structure morphology is changed from needle-like into network structure. Meanwhile, with the increase of Y addition, the tensile strength, hardness, impact toughness are increased with the decrease of plasticity, however, with Y addition more than 6%, impacting toughness of the alloy is slightly declined.