L-PBF in-situ process monitoring instrumentation

提出了一种具有原位发射光谱、真空室和封装空间缩小的激光粉末床熔合(LPBF)装置，以了解(纳米颗粒添加的)金属粉末的加工。通过原位光谱跟踪LPBF过程中的化学成分，并在三维上重建它，对于将化学成分变化与微结构形成和3D器件性能相关联是至关重要的。同时，采用X射线荧光(XRF)和能量色散X射线能谱(EDX)对LPBF加工后的零件进行了元素分析。然而，这种非原位重建方法需要繁琐和耗时的准备工作，很难适用于全三维重建。提出的集成光学发射光谱(OES)的LPBF仪器为现场元素分析提供了一种快速的方法。已经被成功演示用于激光焊接的OES能够对熔化的激光束在粉末床中的各自的二维位置进行原位金属蒸气分析，并通过软件将其组装成3D信息。此外，还将通过非破坏性非原位XRF和EDX横截面作图，计算出原位测量的发射光谱(特别是元素比)与块体成分的相关性。添加激光粉末床熔化(L-PBF)工艺注定要用于OES，因为在这里，三维部件是通过金属粉末材料的局部熔化和凝固而形成的约20至100µm的层状结构。该装置将利用L PBF工艺的成层原理和成层的数字化特性，实时分析加工过程中的激光诱导发射，并对被加工零件的成分进行完整的空间分析。该仪器将使人们能够更好地了解粉末特性、LPBF工艺和微观结构/部件特性链上的过程。因此，拟议的L-PBF现场过程观察仪占据了关键地位，对与会主席的材料科学、制造和物理研究领域产生了杠杆效应。

A laser powder bed fusion (LPBF) device with in-situ emission spectroscopy, vacuum chamber, and package space reduction is proposed to gain understanding of (nanoparticle-additivated) metal powder processing. Tracking the chemical composition during the LPBF process by in-situ spectroscopy and reconstructing it in three dimensions is critical to correlate compositional changes with microstructure formation and 3D device properties. Concomitantly, X-ray fluorescence (XRF) and energy dispersive X-ray spectroscopy (EDX) are used for elemental analysis after LPBF-fabrication of parts. However, such ex situ methods require tedious and time-consuming preparation and are hardly suitable for full 3D reconstruction. The proposed LPBF instrument with integrated optical emission spectroscopy (OES) provides a fast method for in situ elemental analysis. The OES, which has already been successfully demonstrated for laser welding, enables in-situ metal vapor analysis of the respective two-dimensional position of the melting laser beam in the powder bed, which is to be assembled into 3D information by software. In addition, the correlation of the in situ measured emission spectra (especially element ratios) and the bulk composition will be worked out by means of non-destructive ex-situ XRF and EDX mapping of transverse sections. The additive laser powder bed fusion (L-PBF) process is predestined for the use of OES, since here three-dimensional components are built up in layers of about 20 µm to 100 µm by local melting and solidification of metallic powder material. The layer building principle of the L-PBF process and the digital nature of the layer generation will be exploited in the proposed device to analyze the laser-induced emissions in real time during the process and to obtain a complete spatial analysis of the composition of the manufactured part. The instrument will enable better understanding of the processes along the chain of powder properties, LPBF processing and microstructure/part properties. The proposed L-PBF in-situ process observation instrument thus occupies a key position that exerts a leverage effect on the materials science, manufacturing and physics research spectrum of the participating chairs.