Numerical modeling of thermophysical processes in laser-beam welding with formation of a vapor channel

A quasi-two-dimensional mathematical model of laser welding of plates made of a binary alloy with allowance for metal vaporization and formation of a vapor channel is developed. A difference algorithm and a computer code are designed on the basis of this model. Processes of melting, vaporization, and solidification of the alloy of butt-welded aluminum plates are considered numerically as an example. The shape and depth of the vapor channel and welding bath are calculated for given conditions of the radiation power and welding velocity. Based on semi-empirical relations and numerical data obtained, the characteristic size of the dendritic structure of the solidified melt is estimated.