Method and apparatus for welding material by laser beam.

摘要

A laser beam (2) having a circular cross section is irradiated obliquely with respect to a line vertical to a irradiating surface of material (1) including a metal or by shaping the laser beam through an optical system of an irradiation unit, and then the laser beam (3) having an elliptical shape is irradiated on the irradiating surface to thereby suppress weld defects such as weld cracks in weld joints of a difficult-to-weld material such as aluminum alloy. <IMAGE>