The goal of this project is to investigate the Plasma Source Ion Implantation (PSII) process as an environmentally clean surface modification technique for defense related applications. Through this grant, considerable progress has been made in the understanding of the science and technology of the PSII process. A co-axial geometry technique has been developed and patented to deposit coatings on the inside surface of hollow cylinders and may have applications in gun barrels and recoil mechanisms. A perforated, staggered cathode configuration has been devised to deposit complex nitride coatings with properties superior to mono-nitrides. Erosion-resistant chrome-oxide coatings have been deposited and an optical emission spectroscopy diagnostic has been successfully used as a diagnostic for plasma chemistry. Enhancement of adhesion of titanium-nitride coatings to steel has been achieved by the use of titanium interlayers. Research has been conducted on wear-resistant diamond-like carbon coatings in collaboration with Army Research Lab. Computer models have been developed to predict plasma-workpiece interaction for different target shapes. The grant has provided the opportunity to establish interactions between the University of Wisconsin and personnel at Rock Island Arsenal, Corpus Christi Army Depot. Army Research Lab, and the Watervliet Arsenal.