166
6 Behaviors of Keyhole and Weld Pool Under the Effect …
Fig. 6.1 Dynamic coupling of sub-systems in deep penetration laser welding and the influences of
side-blown gas
gas on behavior of keyhole and the weld pool in laser welding process. However, very
little research has been done on how side-blown gas influences the behaviors of weld
pool and keyhole. Based on the previous experimental results, the paper examines the
CO 2 full-penetration laser welding process of titanium alloy in an effort to explore the
influence mechanisms of auxiliary gas flow on behaviors of keyhole and weld pool
in deep penetration laser welding through numerical simulation of fluid dynamics.
6.2 Flow Field of Side-Blown Shielding Gas (for Titanium
Alloy)
Figure 6.2 demonstrates the typical calculation results of shielding gas flow fields
without considering the generation of metallic vapors in a keyhole. In the figure,
the upper left side of the red dashed line shows top-blown gas released from the
CO 2 laser head, while the lower right side displays side-blown gas released from
the side-blowing nozzle. As presented in the figure, the top-blown gas flow and the
side-blown gas flow change their flow directions after they meet and it is obvious
that their confluence direction (indicated by the red dashed line in Fig. 6.2) mainly
6 Behaviors of Keyhole and Weld Pool Under the Effect …
Fig. 6.1 Dynamic coupling of sub-systems in deep penetration laser welding and the influences of
side-blown gas
gas on behavior of keyhole and the weld pool in laser welding process. However, very
little research has been done on how side-blown gas influences the behaviors of weld
pool and keyhole. Based on the previous experimental results, the paper examines the
CO 2 full-penetration laser welding process of titanium alloy in an effort to explore the
influence mechanisms of auxiliary gas flow on behaviors of keyhole and weld pool
in deep penetration laser welding through numerical simulation of fluid dynamics.
6.2 Flow Field of Side-Blown Shielding Gas (for Titanium
Alloy)
Figure 6.2 demonstrates the typical calculation results of shielding gas flow fields
without considering the generation of metallic vapors in a keyhole. In the figure,
the upper left side of the red dashed line shows top-blown gas released from the
CO 2 laser head, while the lower right side displays side-blown gas released from
the side-blowing nozzle. As presented in the figure, the top-blown gas flow and the
side-blown gas flow change their flow directions after they meet and it is obvious
that their confluence direction (indicated by the red dashed line in Fig. 6.2) mainly