Measurement of the high-temperature melt pool region in the laser powder bed fusion (L-PBF) process is a primary focus of researchers to further understand the dynamic physics of the heating, melting, adhesion, and cooling which define this commercially popular additive manufacturing process. This paper will detail the design, execution, and results of high speed, high magnification in-situ thermographic measurements conducted at the National Institute of Standards and Technology (NIST) focusing on the melt pool region of a commercial L-PBF process. Multiple phenomena are observed including plasma plume and hot particle ejection from the melt region. The thermographic measurement process will be detailed with emphasis on the 'measurability' of observed phenomena and the sources of measurement uncertainty. Further discussion will relate these thermographic results to other efforts at NIST towards L-PBF process finite element simulation and development of in-situ sensing and control methodologies.

中文翻译：

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NIST 商业激光粉末床熔化过程的热成像测量

测量激光粉末床熔化 (L-PBF) 过程中的高温熔池区域是研究人员的主要关注点，以进一步了解定义了这种商业流行的增材制造的加热、熔化、粘附和冷却的动态物理学过程。本文将详细介绍在美国国家标准与技术研究院 (NIST) 进行的高速、高倍率原位热成像测量的设计、执行和结果，重点是商业 L-PBF 工艺的熔池区域。观察到多种现象，包括等离子体羽流和熔融区域的热粒子喷射。将详细介绍热成像测量过程，重点是观察现象的“可测量性”和测量不确定性的来源。