Patent ID: 6040549
Filing Date: 2000-03-21
Classification: B23K

Abstract:
A laser beam machining method comprising a preliminary machining step for pretreating a workpiece and a main machining step for machining the workpiece along a final machining locus after a predetermined time period from the preliminary machining step, wherein:the preliminary machining step comprises condensing and focusing a laser beam into a high energy density and a first energy distribution, and irradiating a leading end of a laser beam along the final machining locus, under preliminary machining conditions so as to obtain a first energy density for removing a surface material of the workpiece;the main machining step comprising irradiating the laser beam onto an area of the workpiece from which the surface material has been removed by said preliminary machining step, under main machining conditions so as to obtain a second energy density different from said first energy density and a second energy distribution different from said first energy distribution, for machining the workpiece; andthe preliminary machining step and the main machining step use a same program storing a same machining locus, the preliminary machining step comprising setting the first energy density of the laser beam necessary for removing the surface material in accordance with an amount and a characteristic of the surface material so that the preliminary machining step is performed according to the surface material.