Deep Penetration Welding with High-Power Laser under Vacuum

Abstract

The authors have developed a new chamber for laser welding under the low vacuum conditions achieved by using rotary pumps. High-power disk laser bead-on-plate welding was performed on Type 304 stainless steel and A5052 aluminum alloy plate at the powers of 10, 16 and 26 kW at various welding speeds under low vacuum. Sound welds of more than 50 and 70 mm in penetration depth could be produced in Type 304 at the pressure of 0.1 kPa, the speed of 0.3 m/min and the power of 16 kW and 26 kW, respectively. Similar penetration was achieved in A5052 aluminum alloy. Welding phenomena under low vacuum were also examined by observing the behavior of a keyhole inlet, a molten pool, melt flows and a plume ejected from a keyhole using high speed video cameras. Low interaction between a laser beam and a plume under low vacuum was confirmed by using the probe laser beam method.