Ion beams replace chrome plating

Metal ion implantation is the process of altering surface properties by bombarding with high-energy metal ions. Because the process does not produce a coating, dimensions and bulk properties of the part remain unchanged, and implanted surfaces have no problems with adhesion, residual stress, or poor microstructure. Implanted surfaces can provide wear and/or corrosion resistance comparable with, or superior to, chrome plating. Furthermore, it is a relatively low-temperature process, which enables treatment of materials such as plastics, aluminum, and low-alloy steel. Furthermore, the performance of coatings can be improved by bombarding with ions during or after the coating process. Specifically, high-energy ions applied during deposition have been shown to reduce the required temperature for physical vapor deposition (PVD) systems, overcoming one of the major obstacles to replacing chromium plating with PVD coatings. This article will review the latest advances in metal-ion implantation equipment, with particular reference to economics and applications.