摘要
通过对Mg_(97.5)Y Zn_(0.5)Si_(1)(at.%)和Mg_(96.5)Y Zn_(0.5)Si_(1)(at.%)两种挤压合金进行显微组织观察及力学性能测试,系统分析了Li元素的添加对合金动态再结晶行为、相组成演变及力学性能的影响。采用金相显微镜和扫描电子显微镜(SEM)对合金微观组织进行表征,并通过拉伸试验评价其室温力学性能。研究结果表明,Li的添加可有效细化合金的动态再结晶晶粒,促进第二相由微米级YSi相转变为纳米级MgYZn复合相,从而同步提升合金的强度与塑性。具体而言,合金抗拉强度由214 MPa提高至232 MPa,屈服强度由134 MPa增加至167 MPa,延伸率由21.6%提升至23.6%.该研究说明,适量Li的添加可通过细化晶粒与调控第二相分布,实现镁合金强塑性的协同改善,为开发高性能镁合金提供了一种可行的合金化途径。
This study systematically investigated the effects of lithium(Li)addition on the dynamic recrystallization behavior,phase composition evolution,and mechanical properties of two extruded alloys,Mg_(97.5)Y Zn_(0.5)Si_(1)(at.%)and Mg_(96.5)Y Zn_(0.5)Si_(1)(at.%).The microstructures of the alloys were characterized by optical microscopy and scanning electron microscopy(SEM),and their roomtemperature mechanical properties were evaluated via tensile tests.The results demonstrate that Li addition can effectively refine the dynamically recrystallized grains of the alloy and facilitate the transformation of the second phase from micron-sized YSi phase to nanoscale MgYZn composite phase,thereby synergistically enhancing the strength and ductility of the alloy.Specifically,the tensile strength of the alloy increases from 214 MPa to 232 MPa,the yield strength rises from 134 MPa to 167 MPa,and the elongation improves from 21.6%to 23.6%.This study indicates that appropriate Li addition enables the synergistic improvement of strength and ductility of magnesium alloys through grain refinement and regulation of second-phase distribution,providing a feasible alloying approach for the development of high-performance magnesium alloys.
作者
白帅伟
柳伟
侯华
BAI Shuai−wei LIU Wei;HU Hua(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan Shanxi O30024,China;School of Materials Science and Engineering,North University of China,Taiyuan Shanxi O30051,China)
出处
《铸造设备与工艺》
2025年第6期55-59,65,共6页
Foundry Equipment & Technology
