42
2 Model of Quasi-Steady Weld Pool Dynamics and Numerical Simulation
Fig. 2.11 Temperature distribution and the keyhole shape and its size in XOZ plane
Figure 2.12 shows the temperature field of laser welding of TC4 titanium alloy
cross section and the geometry of laser keyhole. It can be seen that the keyhole is
bilaterally symmetric, but in the direction of thickness, the size of the keyhole gradually decreases. The keyhole resembles a trumpet in appearance. Its outlet diameter is
about 1.4 mm on the upper surface of the workpiece and about 0.3 mm on the lower
surface. The size of the keyhole is affected mainly by the power of the incident laser
beam, the welding speed and the convection velocity of the weld pool. It can be seen
from the experimental observation that the power of incident laser beam is affected
by the plasma flow emitted by the keyhole, and the size and position of the keyhole
Fig. 2.12 Temperature field and corresponding keyhole dimensions in the YOZ plane of the laser
beam centerline
2 Model of Quasi-Steady Weld Pool Dynamics and Numerical Simulation
Fig. 2.11 Temperature distribution and the keyhole shape and its size in XOZ plane
Figure 2.12 shows the temperature field of laser welding of TC4 titanium alloy
cross section and the geometry of laser keyhole. It can be seen that the keyhole is
bilaterally symmetric, but in the direction of thickness, the size of the keyhole gradually decreases. The keyhole resembles a trumpet in appearance. Its outlet diameter is
about 1.4 mm on the upper surface of the workpiece and about 0.3 mm on the lower
surface. The size of the keyhole is affected mainly by the power of the incident laser
beam, the welding speed and the convection velocity of the weld pool. It can be seen
from the experimental observation that the power of incident laser beam is affected
by the plasma flow emitted by the keyhole, and the size and position of the keyhole
Fig. 2.12 Temperature field and corresponding keyhole dimensions in the YOZ plane of the laser
beam centerline