Femto-second Laser irradiation of Metals

PhD student: Lucas ROUSSEAU, ED 488 SIS (Science, Engineering, Health)

ABSTRACT

Four metals Al, Ni, Fe and Ti were irradiated by infrared femtosecond (fs) laser with durations from a few fs to picoseconds and fluences between 1 and 30 J/cm2. After irradiation the surface close regions were analyzed by electron microscopy and by X-ray diffraction at synchrotron source using micrometer sized beams. The analyses revealed a severely modified subsurface region containing residual stresses lattice and defects such as dislocations, stacking faults and deformation twins. The impacted zone is of about 10-50 µm, being the smallest for Fe and increasing for Ti and Ni and finally Al. The laser-matter interaction also was studied numerically by molecular dynamics considering a two-temperature model for the electrons and ions. The experimental and numerical results suggest that the interaction depth is mostly determined by electron-phonon coupling factor of the metal. A large coupling factor leads to a small penetration.
 

 
PUBLICATIONS

CONFERENCES
  • L. Rousseau, J. Jesudian, A. Borbély, X Sedao, N. Peillon, J. P. Colombier, G. Kermouche, Microstructure evolution during direct laser peening of Titanium in the femtosecond and picosecond regime, 14th INTERNATIONAL CONFERENCE ON SHOT PEENING – ICSP14, Milan, Italy, September 4 -7, 2022
  • L. Rousseau, Sz. Kalácska, N. Peillon, X. Sedao , J-P. Colombier, E. S. Ryan, J. Wright and A. Borbély, Femto-second laser induced sub-surface hardening in metals, New Opportunities in Diffraction Microscopy, ESRF - Grenoble - France. 8 - 11 January 2024
  • L. Rousseau, A. Borbély, J. P. Colombier,  G. Kermouche, X Sedao, N. Peillon, Sz. Kalácska, Subsurface characterization of femtosecond-laser peened aluminium, ECRS11 – 11th European Conference on Residual Stresses, Prague, Czech Republic, June 3-7, 2024