Li Jingwei, Li Faguo
School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
Materials (Basel). 2023 Jul 27;16(15):5296. doi: 10.3390/ma16155296.
Although 7055 aluminum alloy is a deformed aluminum alloy and shows excellent mechanical properties after recrystallization and large deformation, through this method, its application range is enriched if rare earth is added, and the rare earth phase dispersion is promoted by heat treatment. This article used optical microscopy, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), micro Vickers hardness, and room temperature stretching methods to study the as-cast 7055-Er ( = 0 wt.%, 0.2 wt.%, 0.4 wt.%, 0.6 wt.%, 0.8 wt.%) aluminum alloy after being subjected to 460 °C × 3 h homogenization and 410 °C × 1 h solid solution + 150 °C × 12 h aging treatment for the changes in its microstructure and properties. The results indicated that: when 0.2 wt.%Er was added to 7055 aluminum alloy after a solution at 410 °C × 1 h and aging at 150 °C × 12 h, the dendrite structure was significantly reduced, the grain thinning was obvious, and the distribution was uniform; the AlCuEr phase appeared in the lamellar eutectic -Mg(Zn,Al,Cu) structure at grain boundaries, and the hardness reached 168.8 HV. The yield strength, tensile strength, and elongation were 542.12 MPa, 577.67 MPa, and 8.36%, respectively.
虽然7055铝合金是一种变形铝合金，在再结晶和大变形后表现出优异的力学性能，但通过这种方法，如果添加稀土，其应用范围会得到扩展，并且通过热处理可促进稀土相的弥散。本文采用光学显微镜、扫描电子显微镜能谱仪（SEM-EDS）、X射线衍射仪（XRD）、显微维氏硬度测试和室温拉伸试验等方法，研究了铸态7055-Er（=0 wt.%、0.2 wt.%、0.4 wt.%、0.6 wt.%、0.8 wt.%）铝合金在经过460℃×3 h均匀化处理以及410℃×1 h固溶+150℃×12 h时效处理后其组织和性能的变化。结果表明：在7055铝合金中添加0.2 wt.%Er，经过410℃×1 h固溶和150℃×12 h时效后，枝晶组织显著减少，晶粒细化明显且分布均匀；在晶界处的片状共晶-Mg(Zn,Al,Cu)组织中出现了AlCuEr相，硬度达到168.8 HV。屈服强度、抗拉强度和伸长率分别为542.12 MPa、577.67 MPa和8.36%。
