
415Machining by Thermal Erosion
12.5 Ion Beam Machining
IBM takes place in a vacuum chamber using charged ions red from an
ion source toward the workpiece by means of an accelerating voltage. The
mechanism of material removal is closely related to the ejection of atoms
from the surface by other ionized atoms (ions) that bombard the work
material. Energies greater than the binding energy of 5–10 eV are needed
to cause the removal of atoms. At higher energies, sufcient momentum
may cause the removal of several atoms from the surface. Furthermore, the
incident ion will become implemented deeper into the material, damaging
it, by displacement o ...