LEACHABLE BACKER FOR ELECTRON BEAM HOLE DRILLING

摘要

BACKER FOR ELECTRON BEAM HOLE DRILLING Disclosed is an electron beam hole drilling process in which the workpiece surface where the hole exits is covered with a backer comprising particulate bonded to itself and the exit surface by a binding agent. The backer enables a hole having substantial uniform symmetry along its length to be drilled and is particularly useful for hollow parts and contoured surfaces. Backers removable by liquifying, melting, dissolution, leaching and the like, are particularly useful for inaccessible exit surfaces. In a preferred embodiment the backer is comprised of a nonmetallic particulate such as glass while the binder is a soluble silicate. EH-6196A