IBED is a physical, non-equilibrium coating process implemented by the simultaneous bombardment of a growing film with an independently controllable beam of energetic atomic particles. The growing film is generated by vacuum evaporation, and the independent beam of particles consists primarily of charged atoms (ions) extracted at high energy from a broad beam ion source. Beams of either inert species (Ne+, Ar+, or Kr+) or reactive species (N+ or O+) can be utilized. Because control of the ion beam is independent of the coating vapor flux, the energy of the ions in the beam can be varied over a wide range and chosen within a very narrow window. This allows a high degree of control over coating nanostructure and optimization of coating properties such as interfacial adhesion, density, grain size/morphology, and internal stresses.
Since IBED is a physical as opposed to a chemical or thermal process the temperature rise during processing can be held below 300 °F so no thermally-induced volumetric changes in bulk properties or physical dimensions are produced. IBED processing combines the benefits of thermal diffusion processing and conventional coating technologies because the coating atoms first penetrate into the substrate to form a case layer in the surface, and then are grown out from this case layer as a thick coating. Formed kinetically instead of thermally, IBED coatings are “ballistically bonded” to the substrate which forms a metallurgical bond that is much stronger than a mechanical or Van der Waals bond thus dramatically improving coating adhesion.
Essentially a line-of-sight process, sources of the reactant fluxes are located so that they simultaneously illuminate the components to be coated (see Figure). The components are mounted to an angling, rotating platen assembly that is used to uniformly expose all critical surfaces of the components to both reactant fluxes. This provides significant benefits when depositing tribological coatings on precision engineered components and tooling.