Open AccessVisualization of laser back-reflection distribution during laser welding
Author(s) -
Petr Horník,
Hana Šebestová,
Jan Novotný,
Libor Mrňa
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1135/1/012015
Subject(s) - laser , optics , materials science , laser beam welding , keyhole , laser power scaling , welding , beam parameter product , far infrared laser , distributed feedback laser , optoelectronics , laser beam quality , physics , laser beams , metallurgy
There are several approaches to weld quality monitoring during laser welding. Reflected laser radiation carries partial information about the welding process. Fibre lasers has usually a built-in diode to detect excessive back-reflected laser radiation to protect the laser source from damage. Reflected laser radiation measured in the laser source is compared with reflected laser radiation measured in the welding head. Moreover, coaxial high-speed imaging with a narrow bandpass filter on laser wavelength is used to visualize the reflected laser radiation. The advantage of this solution is that no additional illumination is needed and the reflected laser intensity and spatial distribution can be obtained from the image. Keyhole inlet dimensions are measured and related to the laser power. The transition between laser welding modes is studied.