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Abstract
Laser powder bed fusion is one of the most commonly used processes by which metal parts are produced through an additive manufacturing approach, and it is currently the topic of extensive research. This paper describes the study of two aspects of the laser powder bed fusion process through the testing of a prototype fusion chamber produced specifically for research purposes. The laser fusion system studied herein utilizes a 2-axis galvanometer scanner system as a means of manipulating the planar position of a laser spot to produce sintering of the powder bed. As the scanner is the primary means of creating relative motion between the laser spot and the powder bed, its performance directly impacts the dimensional accuracy of the final part. As such, one aspect of the laser powder bed fusion process studied and discussed in this paper is the characterization of the scanner’s ability to accurately position the laser spot over the powder surface. The second aspect of the fusion process studied herein is the ability to collect in-situ data on the powder surface immediately before and after the fusion process as a means of improving the understanding of the process and for characterization of the part being produced. The complex metal parts produced by such processes are often very difficult to dimensionally characterize after the build process is complete. Therefore, it is valuable to the industry to measure each layer of the build process, while features that may eventually be obscured are still available for interrogation. This paper describes the development of a metrology system which performs areal height measurements of the powder surface to dimensionally characterize final part geometry on a layer-by-layer basis.