Beam blocking material and method for beam drilling and inspecting cooling holes

摘要

A method of forming and inspecting beam drilled holes (12), and in particular laser beam drilled holes (12), in an article such as a turbine blade (10) or vane airfoil (11), with a hollow interior (16). The method includes (a) filling the hollow interior (16) with a beam blocking material (24) having fluorescent material, (b) beam drilling the holes (12) in a wall (15) through to the hollow interior (16), and (c) inspecting the hole (12) under a black light (30). The beam blocking material (24) preferably includes a wax material and step (a) includes filling the hollow interior (16) with a melted mixture of the wax and fluorescent materials. The wax material may be a pattern wax material suitable for use in making turbine blade (10) investment casting molds and the fluorescent material may be a fluorescent penetrant.