Abstract As the properties of wire + arc additively manufactured Al-6.3Cu alloy cannot meet the applying requirements, a double-wire + arc additive manufacturing system was built to add magnesium into Al-Cu deposits for higher mechanical properties. Two commercial binary wires aluminum-copper ER2319 and aluminum-magnesium ER5087 were chosen as the filler metal to build Al-Cu-Mg components with different compositions by adjusting the wire feed speed. The microstructure and morphology of thin wall samples were characterized by optical micrographs (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The Vickers hardness and tensile properties were investigated. The microstructure of Al-Cu-Mg deposits was mainly composed of coarse columnar grains and fine equiaxed grains with non-uniformly distributing characteristics. With higher Cu but lower Mg content, the strengthen phase turned to Al2Cu + Al2CuMg from Al2CuMg, and the micro hardness presented an increasing trend. The isotropic characteristics of ultimate tensile strength (UTS), yield strength (YS) and elongation were revealed in these samples. The UTS was about 280 ± 5 MPa both in horizontal and vertical directions for all samples. The YS showed an increasing trend from 156 MPa to 187 MPa with the same content trend, while elongation decreased from 8.2% to 6%. The fractographs exhibited typical brittle fracture characteristics.

中文翻译：

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双丝+电弧增材制造Al-Cu-Mg合金的组织和力学性能

摘要 针对焊丝+电弧增材制造的Al-6.3Cu合金性能不能满足应用要求，构建了双焊丝+电弧增材制造系统，在Al-Cu镀层中添加镁以提高其力学性能。选择两种商用二元线铝铜 ER2319 和铝镁 ER5087 作为填充金属，通过调整送丝速度来构建具有不同成分的 Al-Cu-Mg 组件。通过光学显微照片 (OM)、X 射线衍射 (XRD) 和扫描电子显微镜 (SEM) 对薄壁样品的微观结构和形貌进行了表征。研究了维氏硬度和拉伸性能。Al-Cu-Mg 沉积物的显微组织主要由粗大的柱状晶和细小的等轴晶组成，具有非均匀分布的特征。随着Cu含量的增加，Mg含量的降低，强化相由Al2CuMg转变为Al2Cu+Al2CuMg，显微硬度呈增加趋势。在这些样品中揭示了极限拉伸强度 (UTS)、屈服强度 (YS) 和伸长率的各向同性特性。所有样品在水平和垂直方向上的 UTS 约为 280 ± 5 MPa。YS 从 156 MPa 到 187 MPa 呈增加趋势，含量趋势相同，而伸长率从 8.2% 下降到 6%。断口图表现出典型的脆性断裂特征。所有样品在水平和垂直方向上的 UTS 约为 280 ± 5 MPa。YS 从 156 MPa 到 187 MPa 呈增加趋势，含量趋势相同，而伸长率从 8.2% 下降到 6%。断口图表现出典型的脆性断裂特征。所有样品在水平和垂直方向上的 UTS 约为 280 ± 5 MPa。YS 从 156 MPa 到 187 MPa 呈增加趋势，含量趋势相同，而伸长率从 8.2% 下降到 6%。断口图表现出典型的脆性断裂特征。