Investigations of Microstructure and Mechanical Properties in Wire + Arc Additively Manufactured Niobium–Zirconium Alloy
Investigations of Microstructure and Mechanical Properties in Wire + Arc Additively Manufactured Niobium–Zirconium Alloy
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电弧增材制造铌锆合金显微组织与力学性能研究
DOI：
10.1002/adem.202201633
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发表时间：
2023
影响因子：
3.6
通讯作者：
Kim, Duck Bong
中科院分区：
文献类型：
--
作者：
Islam, Saiful;Ahsan, Md. Rumman Ul;Seo, Gi-Jeong;Lee, Ho-Jin;Park, Taejoon;Pourboghrat, Farhang;Kim, Duck Bong
在此基础上，研究了采用钨气弧焊丝+电弧增材制造工艺制备铌- 1wt %锆（NbZr1）合金薄壁结构的可行性。三种不同的热输入条件（低，中，高）已选择制造它。利用光学显微镜、扫描电镜、X射线衍射、能量色散光谱和电子背散射衍射（EBSD）对其微观结构进行了表征。显微组织表现为柱状枝晶组织，在构建方向上拉长。在结构中未观察到裂纹或孔隙。低、中、高热输入条件下的平均维氏硬度分别为146.6、162.1和163.5 HV。显微硬度值沿沉积高度呈增大趋势，这与二次枝晶臂间距和析出相形成的差异有关。试样的抗拉强度可与常规和增材制造的结构相媲美。EBSD分析证实，可能的亚晶粒在室温下具有良好的机械性能。在大多数拉伸试样中，破坏机制已被确定为韧性断裂。各薄壁的力学特性随位置的不同而变化，表明沉积物具有各向异性。
Herein, the feasibility of the gas tungsten arc welding‐based wire + arc additive manufacturing process for fabricating thin wall structures of niobium‐1 wt% zirconium (NbZr1) alloy is investigated. Three different heat input conditions (low, medium, and high) have been selected for fabricating it. The microstructure is characterized by using optical microscopy, scanning electron microscopy, X‐ray diffraction, energy‐dispersive spectroscopy, and electron backscattered diffraction (EBSD). The microstructure shows the columnar dendritic structure elongated in the build direction. No cracks or porosity are observed in the structure. Average Vickers hardness for low, medium, and high heat input conditions are 146.6, 162.1, and 163.5 HV, respectively. There is an increasing trend of microhardness value along the deposition height, which can be attributed to the difference in secondary dendritic arm spacing and the formation of precipitates. The tensile strength of the specimen is comparable to the conventional and additively manufactured structures. EBSD analysis confirms that possible subgrains are responsible for good mechanical properties at room temperature. In the majority of the tensile samples, the failure mechanism has been identified as a ductile fracture. The mechanical characteristics fluctuate with locations in each of the thin walls, suggesting anisotropy in the deposits.