Study on periodical oscillation of plasma/vapor induced in high power fibre laser penetration welding

Abstract

High power fibre laser has been receiving attention because of advantages such as high output power, high beam quality and flexible fibre delivery. Studies on mechanism of fibre laser welding will further promote its practical application. In this paper, high speed video observation was used to study the characterization of plasma/vapor induced during bead on plate welding of ZL114 with high power CW fibre laser and to analysis the reason for periodical oscillation of the plasma/vapor. The results show that plasma/vapor induced with high power laser is oscillated periodically at 450-600 µs cycle above the weld pool surface. Shielding gas has little effect on the oscillation cycle. The main reason for periodical oscillation of the plasma/vapor is the oscillation of the keyhole and the weld pool.High power fibre laser has been receiving attention because of advantages such as high output power, high beam quality and flexible fibre delivery. Studies on mechanism of fibre laser welding will further promote its practical application. In this paper, high speed video observation was used to study the characterization of plasma/vapor induced during bead on plate welding of ZL114 with high power CW fibre laser and to analysis the reason for periodical oscillation of the plasma/vapor. The results show that plasma/vapor induced with high power laser is oscillated periodically at 450-600 µs cycle above the weld pool surface. Shielding gas has little effect on the oscillation cycle. The main reason for periodical oscillation of the plasma/vapor is the oscillation of the keyhole and the weld pool.