Keyhole Modeling during Laser Deep Penetration Welding

Abstract

In order to accurately simulate the process of laser deep penetration welding, a mathematical model to describe laser deep penetration welding was developed by using the heat source derived from the ray-tracing model, and taking account into the effect of keyhole on welding pool. With all the governing equations including continuity, momentum and energy equation, the VOF method is adopted to trace the free surface of the molten pool. Numerical simulation was conducted by FLUENT 6.3 software package. The simulation results show that the formation of keyhole in the weld is caused by recoil pressure.

On the application of the anisotropic enhanced thermal conductivity approach to thermal modelling of laser-based powder bed fusion processes

“…However, this model, as with every model in this discussion up to this point, did not attempt to model the keyhole effect due to laser beam trapping. The physics of keyholing (as described elsewhere [7]) can lead to keyhole porosity and is beyond the scope of work. Recent work by Jakumeit et al [8] modelled the complex gas flows that evaporate from the melt pool.…”

Extraction of Characteristic Parameters of Keyhole during High Power Fiber Laser Welding

“…During deep penetration laser welding, actual welding process is very complicated. A deep cavity called a keyhole is formed in a molten pool due to the intense recoil pressure of evaporation [1]. Although kinds of controlled parameters remain constant, the system of high power fiber laser welding suffers many disturbances and then appears unstable state [2].…”