Laser powder bed fusion (L-PBF) is a dominant process in the fast-emerging additive manufacturing (AM) industry. Despite the many advantages that can be gained by adopting AM, sustained future growth in this industrial sector requires AM to overcome several barriers, most notably, the formation of in-part defects and the high production cost. Motivated by the growing interest of reducing feedstock cost, we studied the cost-efficient hydride-dehydride (HDH) Ti-6Al-4 V powder in L-PBF and show that the in-part porosity can be controlled to produce nearly fully dense (> 99.8% density) components by optimizing process parameters. The process map that was developed with the HDH powder offers a general guideline for the usage of non-spherical powder in powder bed AM. In this work, we investigated the size, morphology, and spatial distribution of the powder-induced porosity in 3D and quantified the interaction between the HDH powder layer and keyhole fluctuation in-situ by utilizing advanced synchrotron-based x-ray computed tomography and dynamic x-ray radiography. With the assistance of a Monte Carlo image-based analysis, we propose two porosity formation mechanisms and attribute them to the unique characteristics of the HDH powder bed, i.e., variable local packing and larger particle size.

激光粉末床融合 ( L- PBF) 是快速兴起的增材制造 (AM) 行业的主要工艺。尽管采用增材制造可以获得许多优势，但该行业未来的持续增长需要增材制造克服几个障碍，最显着的是零件缺陷的形成和高生产成本。受降低原料成本日益增长的兴趣的推动，我们研究了具有成本效益的氢化物脱氢 (HDH) Ti-6Al-4 V 粉末在L-PBF 并表明可以通过优化工艺参数控制零件内孔隙率以生产几乎完全致密（> 99.8% 密度）的部件。使用 HDH 粉末开发的工艺图为在粉末床 AM 中使用非球形粉末提供了一般指南。在这项工作中，我们在 3D 中研究了粉末诱导孔隙的大小、形态和空间分布，并利用先进的基于同步加速器的 X 射线计算机断层扫描和动态原位量化了 HDH 粉末层与锁孔波动之间的相互作用。 X 射线照相术。借助基于蒙特卡罗图像的分析，我们提出了两种孔隙形成机制，并将其归因于 HDH 粉末床的独特特征，即可变的局部堆积和较大的粒径。