Effect of ion energy on the mechanical properties of ion beam assisted deposition (IBAD) wear resistant coatings

Ion beam assisted physical vapor deposition offers a number of advantages over other surface modification methods with respect to the properties of wear resistant coatings. These properties include density, adhesion to the substrate, crystallographic orientation, durability and resistance to degradation by moisture. These improved film properties derive from the physical and chemical processes associated with the impingement of energetic ions onto the surface of a growing film. Such processes include sputtering and desorption of atoms from the substrate, implantation of atoms into the substrate, chemical reactions at the surface, cluster nucleation and dissociation, enhancement of surface diffusion, atomic displacements in the bulk, as well as energy and momentum transfer to the atoms in the growing film. A review of models for the influence of ion energy and momentum transfer to a growing film suggests that the effects of ion bombardment may be categorized according to the ion energy.