Invited Speakers
Prof. Aurelian Marcu
National Institute of Plasma, Laser and Radiation Physics, Magurele, 077125, RomaniaSpeech Title: Non-linear Optic Materials in High Power Laser - Matter Interaction Diagnosis
Abstract: Monitoring both temporal and spatial distributions of transitory electro-magnetic fields represents a challenge with frontier applications. High-power laser-matter interaction is just one of the examples in which such transient electro-magnetic fields are produced, and where such a field monitoring would be of a real interest in characterizing the interaction itself, an interaction otherwise relatively hard to monitor and control. Starting from some previously developed theoretical and experimental correlations between High-Power Laser-Matter interaction parameters and associated pulsed electromagnetic fields (EMP) parameters, here we present some results on magnetic field spatial and temporal measurements, for 2D areas of about 1 cm2 and temporal duration of ms order. System calibration results were performed based on material theoretical parameter values as well as experimentally measured parameter values. Field measurement experimental values are compared with field theoretical calculations as well as other experimental results obtained with different ‘standard’ calibrated tools (e.g. Hall probe). Furthermore, based on Electro-Optical materials, similar results could be obtained for electric field spatial and temporal variations. Comparative results for such systems are presented and discussed, as well as perspectives of such measurement and monitoring techniques in relation with high-power laser-matter interactions characterization and diagnosis.
Keywords: Non-linear optic materials, transitory electro-magnetic field monitoring, laser-matter interactions.
Acknowledgments: We acknowledge funds from the Ministry of Research, Innovation and Digitization / Institute of Atomic Physics, through ELI-RO 30/2024, Eli-RO 30/2025 support of the National Interest Infrastructure facility IOSIN – CETAL at INFLPR and Program contract No. 39/2024, Romanian National Core Program LAPLAS VII contract No. 30N/2023.
Dr. Andrei POPESCU
Center for Advanced Laser Technologies, National Institute for Lasers, Plasma and Radiation Physics, Bucharest, RomaniaSpeech Title: Metal’s Laser Welding Defects Analysis
Abstract: As a Laboratory dedicated to technological transfer in the field of laser welding and additive manufacturing, a significant interest is devoted to the quality control of produced parts. During the development of technologies, we usually monitor in situ the experiments via high-speed imaging and thermography. One of our purposes is to identify as fast as possible the defects, so that to be able to separate the conform parts from the deviant ones non-destructively. If there are no possible associations between features of the plasma plume during laser processing and the defects that appear during processing, X-ray imaging (radiography/tomography) is the selection of choice for non-destructive defects assessment.
The presentation will focus on examples of technologies that are developed for various companies in Romania, that take into consideration the non-destructive defects assessment and possible correlations between processing features and defects outcome in case of processing of metal matrix composites and metal alloys.
Correlations between metallographic analyses and area/intensity of the hot vapor in various locations of the samples help to automize the in-situ quality control of samples. Based on the characterization of the hot vapor, it has been found that the increase of the vapor area that exceeded a threshold value was a sign of pores formation within the weld seam.
In parallel, X-ray tomography allows for fast defects identification, thus reducing the necessity for metallographic preparation of samples and manual optical microscopical observations, thus reducing significantly the time for quality control in case of companies adopting our technologies.
Keywords: laser welding, high-speed imaging, porosity control, hot vapor, process optimization, X-ray imaging characterization
Speakers will be updated…

