Measurement of powder spreading dynamics in additive manufacturing

Ferris, Samuel; Thompson, Adam; Maskery, Ian; Hall, Steven; Piano, Samanta

Abstract

In this work, we examine the effect of the state of the pre-processing powder bed in powder-based additive manufacturing, particularly in metal laser powder bed fusion (PBF-LB). The spreading of the powder layer has been identified as a critical but underresearched stage of the PBF-LB process; the existing literature on PBF-LB predominantly focuses on overall process parameters and the properties of the powder feedstock. Here, we investigate powder spreading dynamics by measuring spread powder surfaces using optical measurement technologies, primarily fringe projection. Measurement technologies are investigated to determine which can be used to provide valuable data about the state of the powder bed. Powders can be immobilised to improve the ease of measurement; in this work, immobilisation is achieved by adhering it to the base of a petri dish, and different adhesives are investigated. Most adhesives used create inhomogeneous surfaces where the texture is determined by the adhesive, as opposed to the powder, and therefore they provide minimal utility in analysing the powder. Experiments are also performed with a machine containing the build surface and powder spreading components used in PBF-LB. Powder is spread across the build surface, as during the PBF-LB process; the resulting unprocessed powder surface is then measured using a fringe projection system. The resulting point cloud is then used to generate a digital surface representing the powder surface, which can be further analysed. This work investigates the measurement of spread powder layers using optical measurement techniques. The method of adhering powders to a base does not provide satisfactory results as the adhesive dominates the surface texture; however, it is possible to measure loose powder insitu using fringe projection and therefore analyse the surface texture of the powder bed. This analysis can be used to indicate the performance of the powder spreading process.

Citation

Ferris, S., Thompson, A., Maskery, I., Hall, S., & Piano, S. (2023). Measurement of powder spreading dynamics in additive manufacturing.

• Conference Name: European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 23rd International Conference and Exhibition, EUSPEN 2023
• Conference Location: Copenhagen, Denmark
• Start Date: Jun 12, 2023
• End Date: Jun 16, 2023
• Acceptance Date: Jan 1, 2023
• Publication Date: Jun 16, 2023
• Deposit Date: Jan 9, 2024
• Pages: 401-404
• ISBN: 9781998999132
• Public URL: https://nottingham-repository.worktribe.com/output/26811905
• Publisher URL: https://www.euspen.eu/knowledge-base/ICE23189.pdf
• Related Public URLs: https://www.euspen.eu/events/23rd-international-conference-exhibition-12th-16th-june-2023-2/?subid=23rd-international-conference-exhibition-12th-16th-june-2023-2