【摘要】 采用光学显微镜、扫描电镜、万能拉伸试验机等研究了不同预拉伸量(0%、5%、10%)及时效处理对挤压态Mg-4Gd合金组织和力学性能的影响。结果表明：增加预拉伸量会增加时效过程中形成的具有不规则多面体结构及Gd含量相对较低的第二相的数量，其尺寸随时效时间的延长而增加。当预拉伸量从0%增加至5%和10%时，合金的强度不断增加，但增幅逐渐减小，伸长率先迅速下降后趋于稳定。预拉伸处理与时效处理相结合可提高合金的强度但降低了伸长率，其中预拉伸10%合金在峰时效工艺下的屈服强度提高至136.29 MPa、抗拉强度提高至241.48 MPa、伸长率则降低至12.49%。与预拉伸处理相比，时效处理后合金的硬化能力和加工硬化指数值降低。合金的加工硬化率主要受预拉伸工艺的影响，但可通过后续时效处理进行有效控制。更多还原

【Abstract】 Effect of different pre-stretching amounts(0%, 5% and 10%) and aging treatment on microstructure and mechanical properties of extruded Mg-4Gd alloy was studied by means of optical microscope, scanning electron microscopy and universal tensile testing machine. The results indicate that increasing the pre-stretching amount will increase the number of second phases with irregular polyhedral structures and relatively low Gd content formed during the aging process, and their size will increase with the increase of aging time. When the pre-stretching amount increases from 0% to 5% and 10%, the strength of the alloy continuously increases, but the increment gradually decreases, and the elongation first rapidly decreases and then stabilizes. The combination of pre-stretching treatment and aging treatment can improve the strength of the alloy but reduce the elongation. Among them, the yield strength of the alloy with pre-stretching of 10% under peak aging process is increased to 136.29 MPa, the tensile strength is increased to 241.48 MPa, and the elongation is reduced to 12.49%. Compared with pre-stretching treatment, the value of hardening ability and work hardening index of the alloy after aging treatment decrease. The work hardening rate of alloys is mainly affected by the pre-stretching process, but can be effectively controlled through subsequent aging treatment.更多还原