Abstract Considering the wide applications of Laser Directed Energy Deposition (LDED) based Additive Manufacturing built Inconel718 (IN718) bulk structures, fatigue crack propagation (FCP) studies are performed on LDED built IN718 structures at two different scan strategies (Z-pattern-0 and Z-pattern-90) for the first time. Microscopic analysis shows that the built structures are defect-free with slightly fine dendritic growth for Z-pattern-90 samples. FCP tests reveal striations ≤ 200 nm and show about 2.5 times higher FCP resistance for Z-pattern-90 as compared to Z-pattern-0. FCP resistance of thus built samples is observed to be in between forged and Laser Powder Bed Fusion built samples. This study provides an understanding of the FCP behaviour of LDED built IN718 for various engineering applications.

中文翻译：

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使用基于定向能量沉积的激光增材制造构建的 Inconel 718 结构的疲劳裂纹传播行为

摘要 考虑到基于激光定向能量沉积 (LDED) 的增材制造制造的 Inconel718 (IN718) 块体结构的广泛应用，疲劳裂纹扩展 (FCP) 研究以两种不同的扫描策略（Z-pattern-0 和Z-pattern-90）第一次。显微分析表明，Z-pattern-90 样品的构建结构无缺陷，枝晶生长略细。FCP 测试显示条纹≤ 200 nm，与 Z-pattern-0 相比，Z-pattern-90 的 FCP 电阻高出约 2.5 倍。观察到由此构建的样品的 FCP 抗性介于锻造和激光粉末床融合构建的样品之间。本研究为各种工程应用提供了对 LDED 内置 IN718 的 FCP 行为的理解。