Powder particle–wall collision-based design of the discrete axial nozzle-exit shape in direct laser deposition

Jeromen, Andrej (author), Vidergar, Ana (author), Fujishima, Makoto (author), Levy, Gideon N. (author), Govekar, Edvard (author)

To improve the efficiency of the direct laser deposition (DLD) of metal powders, a concentrated powder-stream distribution is required, which can be affected by the shape of the powder-delivery nozzle. In this study, a simplified, powder particle–wall collision-based 3D numerical model of the powder flow in the nozzle was used to simulate the influences of the nozzle-exit shape on the concentration of the powder stream distribution, characterized by its diameter. The nozzle-exit shape was parametrized by the exit-cone angle, length, and inner-surface roughness. Based on the simulation results, the nozzle-exit shapes of three exit-cone angles (0°, 3.5° and 7.2°), various lengths and surface-roughness values were designed. For the two larger particle sizes of 22 μm and 82 μm considered, the wall-collision-dominated regime and the influence of the nozzle-exit shape were experimentally confirmed. In particular, a significant decrease in the powder-stream diameter when increasing the divergent nozzle-exit cone angle or decreasing its surface roughness and the nonlinear influence of the cone length were shown. Using single-layer, powder-deposition experiments it was demonstrated that by modifying the design of the nozzle-exit shape, the powder-catchment efficiency was increased by 13% due to the increased nozzle-exit cone angle and by 19% due to the reduced surface roughness.

• Language: English
• Keywords: direct laser deposition, axial nozzle shapes, wall-collision-dominated flow, powder-stream distribution, powder-catchment efficiency
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2022
• Number of pages: 13 str.
• Numbering: Vol. 308, art. 117704
• PID: 20.500.12556/RUL-138253
• UDC: 621.7
• ISSN on article: 0924-0136
• DOI: 10.1016/j.jmatprotec.2022.117704
• COBISS.SI-ID: 114823683
• Publication date in RUL: 13.07.2022

Record is a part of a journal

• Title: Journal of materials processing technology
• Shortened title: J. mater. process. technol.
• Publisher: Elsevier
• ISSN: 0924-0136
• COBISS.SI-ID: 30105600

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: neposredno lasersko nanašanje, aksialna oblika šob, trčenje sten v prevladujočem toku, porazdelitev toka prahu, učinkovitost zajemanja prahu

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0241
• Name: Sinergetika kompleksnih sistemov in procesov

• Funder: Other - Other funder or multiple funders
• Funding programme: DMG Mori Co., Ltd.