Operando X-ray diffraction and imaging

A miniaturized laser powder bed fusion device was developed to perform operando X-ray diffraction and imaging experiments at synchrotron facilities. This portable device exhibits the basic functionalities of a commercial LPBF device. 

miniSLM

A collimated infrared laser beam is deflected by a 2-axis scanning unit into the main chamber. The laser beam is focused onto a 12 × 12 mm2 build stage that can be translated vertically with a travel range of 12 mm and sub-micron step size. The build stage can be heated using a silicon-nitride resistive heater. Powder recoating is based on a hopper feeding system. The powder reservoir can be moved across the baseplate with the aid of a motor-spindle assembly. The device is completely closed, preventing laser light or particles to escape. The chamber is continuously flushed with high purity argon gas. With the aid of manual flowmeters, a slight overpressure is created in the chamber to avoid oxygen contamination by the outside atmosphere. The whole setup (laser, scanning unit and printing chamber) is cooled down with a closed-loop air-water exchange based chiller.  An inline optical camera allows aligning the laser and inspecting the powder bed. The video below describes the basic principle behind operando X-ray diffraction during SLM. 

Laser    
  Type redPOWER® continuous wave Fiber Laser
  Wavelength 1070nm
  Maximum power 500W
  Spot size 25 µm - 250 µm
Device    
  Dimensions 15mm x 20mm x 30mm
  Build plate 12mm x 12mm
  Maximum build height 8mm
  Maximum temperature 150°C
  Maximum angle tilt stage 20°
  • Hamidi Nasab M, Masinelli G, de Formanoir C, Schlenger L, Van Petegem S, Esmaeilzadeh R, et al.
    Harmonizing sound and light: X-ray imaging unveils acoustic signatures of stochastic inter-regime instabilities during laser melting
    Nature Communications. 2023; 14: 8008 (14 pp.). https://doi.org/10.1038/s41467-023-43371-3
    DORA PSI
  • Gao S, Li Z, Van Petegem S, Ge J, Goel S, Vas JV, et al.
    Additive manufacturing of alloys with programmable microstructure and properties
    Nature Communications. 2023; 14(1): 6752 (11 pp.). https://doi.org/10.1038/s41467-023-42326-y
    DORA PSI
  • Hocine S, Van Swygenhoven H, Van Petegem S
    Verification of selective laser melting heat source models with operando X-ray diffraction data
    Additive Manufacturing. 2021; 37: 101747 (16 pp.). https://doi.org/10.1016/j.addma.2020.101747
    DORA PSI
  • Hocine S, Van Petegem S, Frommherz U, Tinti G, Casati N, Grolimund D, et al.
    A miniaturized selective laser melting device for operando X-ray diffraction studies
    Additive Manufacturing. 2020; 34: 101194 (9 pp.). https://doi.org/10.1016/j.addma.2020.101194
    DORA PSI
  • Hocine S, Van Swygenhoven H, Van Petegem S, Chang CST, Maimaitiyili T, Tinti G, et al.
    Operando X-ray diffraction during laser 3D printing
    Materials Today. 2020; 34: 30-40. https://doi.org/10.1016/j.mattod.2019.10.001
    DORA PSI
Basic principle of operando X-ray diffraction during selective laser melting.
(Credit: Paul Scherrer Institute/Mahir Dzambegovic)