Laser welding apparatus and method for high temperature gradient cooling alloys

摘要

Metal alloy workpieces are laser welded to one another with a laser head emitting a laser beam. The laser head and workpieces are moved relative to one another at a predetermined velocity along a weld path. The laser beam power is selectively modulated to have an output with a desired frequency and/or amplitude. An oscillating motion of the laser beam is superimposed on top of the relative velocity of movement between the laser head and the workpieces along the weld path, such that a rate of cooling of molten metal is controlled to a predetermined rate. A stroke rate of the oscillating motion is synchronized with the frequency of the modulated power output so that as the laser head moves along the weld path at a constant velocity, the laser beam is oscillated to thereby cause the laser beam to at least slow down relative to the velocity of travel between the laser head with respect to the workpieces along the weld path during backward oscillatory movement of the laser beam.