Microstructure and mechanical properties of high-performance Mg–Y–Er–Zn extruded alloy
Microstructure and mechanical properties of high-performance Mg–Y–Er–Zn extruded alloy
复制标题
DOI：
10.1016/j.matdes.2013.08.048
复制
发表时间：
2014-02
影响因子：
8.4
通讯作者：
Li Zhang;Jinghuai Zhang;Zhe Leng;Shujuan Liu;Qiang Yang;R. Wu;Milin Zhang
中科院分区：
文献类型：
--
作者：
Li Zhang;Jinghuai Zhang;Zhe Leng;Shujuan Liu;Qiang Yang;R. Wu;Milin Zhang
采用热挤压技术并进行时效处理，制备了具有高强度、高塑性和耐热性的Mg-8Y-1Er-2Zn（wt.%）合金。研究了显微组织和力学性能。结果表明，长周期堆叠有序（LPSO）相与普通非金属材料不同，前者可以通过塑性变形而弯曲，并与镁基体呈现良好的结合。挤压态合金良好的力学性能主要归功于18R LPSO结构的片状带材以及显微组织的细化。 220℃时效处理可以进一步提高强度但不牺牲塑性。挤压态合金在峰值硬度下的极限拉伸强度 (UTS) 和断裂伸长率 (ε) 在室温下分别为 390 MPa 和 18%，在 250 °C 下分别为 322 MPa 和 30%。 14H LPSO结构中细小、高数密度的α-Mg再结晶晶粒的形成是挤压合金在峰值时效后具有优异力学性能的主要原因。
The Mg–8Y–1Er–2Zn (wt.%) alloy with high strength, plasticity and heat-resistance was prepared by the hot extrusion technique and the following aging treatment. The microstructure and mechanical properties were investigated. The results show that long period stacking ordered (LPSO) phase is different from common inermetallics, and the former can be bent by plastic deformation and presents good combination with the Mg matrix. The good mechanical properties of as-extruded alloy are mainly attributed to the lamellar strips with 18R LPSO structure as well as the microstructure refinement. Aging treatment at 220 °C can further improve the strength but not at the expense of plasticity. The ultimate tensile strength (UTS) and elongation to failure (ε) of as-extruded alloy at peak hardness are 390 MPa and 18% at room temperature, and 322 MPa and 30% at 250 °C, respectively. The formation of fine α-Mg recrystallization grains with high number density of 14H LPSO structure is mainly responsible for the superior mechanical properties of extruded alloy after peak-aging.