| 摘要 |
PURPOSE:To increase efficiency of utilization of laser beam energy and perform uniform welding of high quality in performing welding melting added metal by a laser beam, by supplying plasma forming gas to the vicinity of the weld zone. CONSTITUTION:The focal point of a laser beam irradiator 1 is placed near the surface of a material 2 to be welded, and specified quantity of rare gas such as He, Ar etc. or mixed gas of the rare gas added CO2 or O2 is supplied to the point of incidence of the laser beam 3 to the base metal 2 through a gas flow passage 4. This gas is irradiated by the beam 3 near the weld zone and forms plasma atmosphere, and the beam 3 is incident upon the weld zone through the atmosphere. An added metal wire is fed to the beam 3 by a feeder 7 through a guide 8. Before the tip of the wire arrives at the beam, it is molten by the heat of plasma atmosphere and moves to the upper part of butted part of welded end faces, and forms a bridge. This is heated and kept hot by the plasma atmosphere and mixes with molten metal at welded end faces. |
