Investigation of Shielding Gas Supplying Method in Vertical-position Laser Welding of Pure Titanium

Effective shielding method for a wide area is required in the vertical-position remote laser welding of pure titanium. Therefore, shielding effects of ring-type nozzles with two layers for a wide area were numerically and experimentally investigated in the vertical-position setup of workpiece with argon gas. Prevention of incoming air flow outside a ring-type nozzle is effective to increase mass fraction of argon gas. Mass fraction of argon gas could be increased using a ring-type nozzle, in which shielding gas is supplied by open-side injection ports of proper angle at a proper flow ratio of two jetting layers.