This research proposes a novel variant of wire-laser directed energy deposition (DED), named beam oscillating wire-laser DED. In this technique, the laser beam oscillates periodically in an 8-shape or infinite pattern to control the forming quality and geometries of the deposited layer. The novelty is that how the laser oscillating pattern, frequency, and amplitude affect the forming qualities and deposition layer dimensions. The study investigates the dynamic behaviors of the molten pool and the generation mechanisms of various forming defects. A comparison is made with non-oscillating wire-laser DED regarding the thin-wall part’s forming qualities. The results reveal that the layer width of the 8-shape oscillating sample increases when the oscillating amplitude increases. However, the infinite oscillating sample behaves inversely. The width-to-height ratio of the deposition layer varies from 2.04 to 5.18 by changing the laser oscillating pattern and amplitude. Compared to non-oscillating wire-laser DED, the surface quality and the structure density of the deposited walls by beam oscillating wire-laser DED show remarkable improvement. The wall’s material utilization rate is increased by 22.2 % with the 8-shape oscillation. This study demonstrates the ability of beam oscillating wire-laser DED to control the deposition layer dimensions and improve the forming quality without compromising the deposition efficiency.

中文翻译：

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光束振荡线激光定向能量沉积中的熔池行为和形成特征

这项研究提出了一种新型线激光定向能量沉积 (DED)，称为光束振荡线激光 DED。在该技术中，激光束以 8 字形或无限图案周期性振荡，以控制沉积层的成形质量和几何形状。新颖之处在于激光振荡模式、频率和振幅如何影响成形质量和沉积层尺寸。该研究研究了熔池的动态行为和各种成形缺陷的产生机制。在薄壁零件的成形质量方面，与非振荡线激光 DED 进行了比较。结果表明，当振荡幅度增大时，8字形振荡样品的层宽增大。然而，无限振荡样本的行为却相反。通过改变激光振荡模式和振幅，沉积层的宽高比从2.04变化到5.18。与非振荡线激光DED相比，振荡线激光DED沉积壁的表面质量和结构密度都有显着改善。8字形摆动，墙体材料利用率提高22.2%。这项研究证明了光束振荡线激光 DED 能够在不影响沉积效率的情况下控制沉积层尺寸并提高成形质量。