Patent ID: 7186946
Filing Date: 2007-03-06
Classification: B23K

Abstract:
1. A method of laser drilling a workpiece, the method comprising: directing a laser beam at the surface of a workpiece to be drilled by the laser beam; directing a jet of assist gas toward the point of incidence of the laser beam on the workpiece; wherein the jet of assist gas is directed toward the workpiece at an angle in the range of 5 to 75 degrees with respect to the laser beam; wherein the workpiece comprises a nozzle guide vane segment of a gas turbine engine having two or more aerofoil sections with a nozzle entry, throat and exit section between adjacent aerofoil sections; and wherein the laser beam is directed in a first direction through one of the nozzle entry or exit sections of an adjacent pair of aerofoils onto the surface of one of the aerofoil sections to be drilled by the laser, and the jet of assist gas is directed to the point of incidence of the laser beam on the aerofoil surface in a second direction through the other of the entry or exit sections.