Mathematical modeling of laser welding with keyhole

A numerical model for a deep penetration laser welding is developed. It consists of the quasi-steady-state three dimensional heat flow model and the three dimensional keyhole surface model. In the model analysis, the recoil pressure due to vaporization is taken into account for the keyhole process and a line heat source of finite depth is proposed to estimate the heat input from the keyhole. Numerical results show that the vaporization of base metal affects the keyhole surface geometry and the depth of it affects pool profile remarkably. The calculated molten pool profiles are also compared with the experimental profiles and it is confirmed that this model is useful for the prediction of laser welded pool profile qualitatively.