Modelling of fume particle behaviour and coupling glass contamination during vacuum laser beam welding

Vacuum laser beam welding utilises the advantages of both laser and electron beam welding. In this study, a numerical model was developed to simulate fume particle behaviour and the contamination of coupling glass through which the laser beam irradiates the vacuum chamber. Supplying a proper flow rate of shielding gas suppresses the infiltration of fume particles into the protective system and prevents the rising of fumes inside the system. The high momentum of the supplied gas could discharge fume particles out of the protective system and horizontally deflect fume particles away. The developed numerical model showed a good agreement with the experimental results, and a systematic method for designing and optimising the protective system was established.