Pore formation is an important concern in laser welding of automotive aluminium alloys. This paper investigates the influence of laser beam defocus on pore formation during continuous wave Nd:YAG laser welding of 5182 and 5754 automotive aluminium alloys. It was found that the instability of the keyhole during welding was a dominant cause of pore formation while hydrogen rejection played an insignificant role. The defocusing of the laser beam greatly affected the stability of the keyhole. Finally, the mechanism of keyhole collapse and pore formation is proposed.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys