Influence of the laser-beam intensity distribution on the performance of directed energy deposition of an axially fed metal powder

Vidergar, Ana (author), Jeromen, Andrej (author), Govekar, Edvard (author)

This paper investigates the influence of laser-beam intensity distribution (LBID) on the performance of the annular laser-beam directed energy deposition (DED) process with axial powder delivery. Three different LBIDs: Gaussian-like (G-LBID), top-hat-like (TH-LBID) and ring (R-LBID) at two LBID diameters were used. The process performance was characterised qualitatively in terms of the melt-pool shape and the process stability and quantitatively by powder-catchment efficiency, selected geometrical and metallurgical properties of the clad. The observed influence of LBID on process performance, as determined by the relationship between LBID and powder stream density distribution (PSDD), decreased with increasing mean surface-energy density and was more significant at larger LBID diameter. The highest powder-catchment efficiencies (90% and 87%) were achieved with the G-LBID and TH-LBID, whose high-intensity centre is aligned with the peak of the Gaussian-like PSDD. A lower powder-catchment efficiency of 77% was achieved with the R-LBID, whose high-intensity region is located at the edge of the melt pool with minimum powder density. However, this also results in the highest and most uniform dilution, the highest metallurgical bond ratio and the lowest lack of fusion porosity at the clad-substrate interface. In addition, the process was stable at the lower values of mean surface-energy density with R-LBID, while balling instability was observed with G-LBID and TH-LBID. It can be concluded that the use of R-LBID at lower values of mean surface-energy density improves the performance of the DED process with axial powder feed in terms of process stability and metallurgical properties of the clad.

• Language: English
• Keywords: directed energy deposition, annular laser beam, laser-beam intensity distribution, powder-catchment efficiency, process stability, clad properties
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 16 str.
• Numbering: Vol. 327, art. 118360
• PID: 20.500.12556/RUL-155540
• UDC: 621.7:535
• ISSN on article: 1873-4774
• DOI: 10.1016/j.jmatprotec.2024.118360
• COBISS.SI-ID: 188192515
• Publication date in RUL: 05.04.2024

Record is a part of a journal

• Title: Journal of materials processing technology
• Shortened title: J. mater. process. technol.
• Publisher: Elsevier
• ISSN: 1873-4774
• COBISS.SI-ID: 118847235

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: lasersko usmerjeno nanašanje, anularni laserski žarek, porazdelitev intenzitete laserskega žarka, izkoristek prahu, stabilnost procesa, lastnosti nanosa

Projects

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