Laser Additive Manufacturing using directed energy deposition of Inconel-718 wall structures with tailored characteristics
Laser Additive Manufacturing using directed energy deposition of Inconel-718 wall structures with tailored characteristics
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DOI：
10.1016/j.vacuum.2019.05.027
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发表时间：
2019-08-01
期刊：
影响因子：
4
通讯作者：
Bindra, K. S.
中科院分区：
文献类型：
--
作者：
Jinoop, A. N.;Paul, C. P.;Bindra, K. S.
开发了一种工艺窗口，用于使用定向能量沉积 (LAM-DED) 制造用于激光增材制造的薄壁 Inconel 718 (IN718) 结构。内部开发的 LAM-DED 设置用于研究工艺参数对几何形状和质量的影响。还研究了后热处理对显微组织、表面和机械性能的影响。进行全面的析因实验来推导出产生所需几何形状、沉积速率和质量的工艺窗口。优化的工艺参数用于薄壁制造。实验发现，对于制造所需几何形状的薄壁，每单位长度的激光能量 (E) 和每单位长度的送粉速率 (F) 的最大和最小限制分别为 210 kJ/m、105 kJ/m、12.5 g/m 和 4 g/m。观察到所制造的薄壁没有缺陷，具有树枝状微观结构。热处理样品的显微结构检查显示出再结晶的等轴晶粒，表面拉伸残余应力降低高达 50%，并且表面形貌发生了变化。研究期间观察到平均硬度降低了 12%，延展性显着提高了 62.5%，储能容量提高了 2.4 倍。
A process window is developed for fabricating thin walled Inconel 718 (IN718) structures for Laser Additive Manufacturing using Directed Energy Deposition (LAM-DED). In-house developed LAM-DED setup deployed to investigate the effect of process parameters on geometry and quality. The influence of post-heat treatment on microstructure, surface and mechanical properties is also studied. Full factorial experiments are carried out to derive the process window yielding requisite geometry, deposition rate and quality. The optimized process parameters are deployed for thin wall fabrication. The maximum and minimum limits for laser energy per unit length (E) and powder feed rate per unit length (F) are experimentally found to be 210 kJ/m, 105 kJ/m, 12.5 g/m and 4 g/m, respectively for fabricating thin walls of requisite geometry. The fabricated thin walls are observed to be defect free with dendritic microstructure. The microstructural examination of heat-treated samples reveals recrystallized equiaxed grains with reduction in surface tensile residual stress up to 50%, and modified surface topography. The reduction of average hardness by 12%, significant improvement in ductility by 62.5% and improvement in energy storage capacity by 2.4 times are observed during the study.