Ion-assisted surface modification by plasma immersion ion implantation

Plasma immersion ion implantation can add high-energy ion bombardment to almost any plasma-based surface treatment. It can be used as a non-line-of-sight alternative to ion-beam implantation, for high-energy ion nitriding or high-energy ion-assisted deposition. This paper describes its use for the treatment of steels at temperatures in the range 200 to 450 degrees C, where it can be considered as a hybrid of ion nitriding and ion implantation. It has been particularly successful in the treatment of austenitic stainless steels, although the results presented in this paper indicate that the high-energy ion bombardment is not always essential (although often desirable) to achieve satisfactory results. While it is shown that the process can open new parts of parameter space and extend known processes to a wider range of materials, the limitations on its use are also discussed. (C) 1998 Elsevier Science S.A.