Plasma source ion implantation (PSII) is a non-line of sight process for im
planting complex shaped targets without the need for complex fixturing. The
breakdown initiation of materials coated with diamondlike carbon (DLC) pro
duced by PSII occurs at defects in the DLC, which expose the underlying mat
erial, thus establishing a galvanic couple between the coating and exposed
material at the base of the defect. Fitting and oxidation of the base metal
leads to the development of mechanical stress in the coating and eventuall
y spallation of the coating. This paper presents current progress in attemp
ting to mitigate the breakdown of these coatings by implanting the par ent
material before coating with DLC. Ideally the parent material would be impl
anted with chromium or molybdenum, which are known to improve corrosion res
istance, however the necessary organormetallics needed to implant these mat
erials with PSII are not yet available. Here the effects of carbon, nitroge
n, and boron implantation on the susceptibility of PSII DLC coated mild ste
el to breakdown are reported. (C) 1999 IoM Communications Ltd.