Description

High-power laser interaction with metal material can induce melting and even evaporation. However, the origin and content of vapor emissions based on temperature, material alloy elements and other external conditions are not fully understood yet. Therefore, in this study, the content of laser-induced vapor was systematically examined during directed energy deposition processes. Single tracks of aluminum bronze were deposited with both continuous and periodically modulated laser power. The duration and laser power of the modulations were set to achieve the same total line energy input. With the aid of those laser power modulations, controlled emissions were temporarily excited and observed. Optical emissions were captured with a spectrometer and a high-speed camera and related to the melt pool temperature signals and surface dynamics. The intensity of the emissions as well as the impact on the local chemical composition depend on the modulation parameters. Tracks deposited with short, high-power peaks in the modulation pattern showed chemical compositions comparable to those tracks that were continuously welded, whereby the intensity of spectral emissions was significantly increased. It can be concluded that the intensity of the measured spectral emissions correlates with the measured melt pool temperature signal and the dynamic movement of the vapor plume.

Contributing Authors

  • Malte Schmidt
    Jade University of applied sciences
  • Knut Partes
    Jade University of applied sciences
  • Himani Naesstroem
    Luleå University of Technology
  • Jörg Volpp
    University West
Malte Schmidt
Jade University of applied sciences
Track: Laser Additive Manufacturing
Session: Powder Bed Fusion I
Day of Week: Tuesday
Date/Time:
Location: Echo Park

Keywords

  • Directed Energy Deposition
  • High-Speed-Imaging
  • Laser-Material Interaction
  • Optical Emission Spectroscopy
  • Process Monitoring