Institute of Digital Engineering, University of Applied Sciences Würzburg Schweinfurt, 97070 Würzburg, Germany.
Bavarian Center of Applied Energy Research e.V., 97074 Würzburg, Germany.
Sensors (Basel). 2022 Aug 9;22(16):5943. doi: 10.3390/s22165943.
Additive manufacturing processes, particularly Laser-Based Powder Bed Fusion of Metals (PBF-LB/M), enable the development of new application possibilities due to their manufacturing-specific freedom of design. These new fields of application require a high degree of component quality, especially in safety-relevant areas. This is currently ensured primarily via a considerable amount of downstream quality control. Suitable process monitoring systems promise to reduce this effort drastically. This paper introduces a novel monitoring method in order to gain process-specific thermal information during the manufacturing process. The Synchronized Path Infrared Thermography (SPIT) method is based on two synchronized galvanometer scanners allowing high-speed and high-resolution observations of the melt pool in the SWIR range. One scanner is used to steer the laser over the building platform, while the second scanner guides the field of view of an IR camera. With this setup, the melting process is observed at different laser powers, scan speeds and at different locations with respect to the laser position, in order to demonstrate the positioning accuracy of the system and to initially gain thermal process data of the melt pool and the heat-affected zone. Therefore, the SPIT system shows a speed independent overall accuracy of ±2 Pixel within the evaluated range. The system further allows detailed thermal observation of the melt pool and the surrounding heat-affected zone.
增材制造工艺，特别是金属的激光粉末床熔合（PBF-LB/M），由于其制造特定的设计自由度，为新的应用可能性的发展提供了可能。这些新的应用领域需要高度的组件质量，特别是在与安全相关的领域。目前，这主要是通过大量的下游质量控制来保证的。合适的过程监控系统有望大大减少这方面的工作。本文介绍了一种新的监测方法，以便在制造过程中获得特定于工艺的热信息。同步路径红外热成像（SPIT）方法基于两个同步的振镜扫描仪，允许在 SWIR 范围内对熔池进行高速和高分辨率的观察。一个扫描仪用于将激光引导到构建平台上，而第二个扫描仪则引导红外相机的视场。通过这种设置，在不同的激光功率、扫描速度以及相对于激光位置的不同位置观察熔化过程，以证明系统的定位精度，并初步获得熔池和热影响区的热过程数据。因此，SPIT 系统在评估范围内的整体精度为±2 像素，与速度无关。该系统还允许对熔池和周围热影响区进行详细的热观察。
