Influence of particle size on powder velocity distribution at the nozzle outlet in Directed Energy Deposition

Mede, Tijan (author), Jeromen, Andrej (author), Govekar, Edvard (author), Mallon, Michael (author), Godec, Matjaž (author)

Metal-based Directed Energy Deposition (DED) is considered one of the variations of additive manufacturing with the highest potential, particularly for space industry and in-orbital manufacturing. The technology however still faces various challenges, many of which can be traced back to poor control and understanding of the powder delivery. Velocity distribution of powder particles at the DED nozzle outlet has a key influence on the results of any predictive model of powder stream and yet remains largely disputed. Certain numerical studies highlighted a possible influence of powder particle size on the velocity condition at the nozzle exit, yet no experimental studies confirmed this effect. The experimental campaign described in this paper quantifies this relation between powder particle size and velocity distribution at the nozzle outlet and a strong decrease of particle speed with particle size is observed. Moreover, smaller particles are observed to travel at speeds higher than the mean carrier gas speed suggesting powder particle segregation within the nozzle as one of the mechanisms driving speed differences at the nozzle outlet.

• Language: English
• Keywords: directed energy deposition, powder stream, boundary conditions, particle velocity distribution
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 10 str.
• Numbering: Vol. 259, art. 114680
• PID: 20.500.12556/RUL-173515
• UDC: 621.791.72
• ISSN on article: 0264-1275
• DOI: 10.1016/j.matdes.2025.114680
• COBISS.SI-ID: 230759683
• Publication date in RUL: 18.09.2025

Record is a part of a journal

• Title: Materials & design
• Shortened title: Mater. des.
• Publisher: Scientific and Technical Press
• ISSN: 0264-1275
• COBISS.SI-ID: 10626075

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Secondary language

• Language: Slovenian
• Keywords: lasersko direktno navarjanje, tok delcev, robni pogoji, porazdelitev hitrosti delcev