A REVIEW OF RECENT DEVELOPMENTS IN ION-IMPLANTATION FOR METALLURGICAL APPLICATION

Ion implantation emerged during the 1970s as a possible tool for improving the wear and corrosion resistance of metals and alloys. This emergence led to a period of intense activity in the early 1980s, aimed at identifying opportunities for the industrial application of ion implantation. This paper reviews the progress which has been made towards establishing ion implantation as an effective and reliable technique for improving the wear resistance of engineering materials. Particular emphasis is placed on the implantation of nitrogen. It is shown how detailed metallurgical studies have elucidated the role played by the implanted nitrogen in enhancing the resistance to wear of a broad range of alloys. These studies have highlighted the fact that the thin nature of the implanted layer has been a prime factor in restricting the industrial usage of ion implantation to a narrow range of specialized applications. This has resulted in a shift to the development of duplex treatments involving two-stage processes or, more recently, new techniques which allow simultaneous implantation and thermochemical treatment. The capabilities of, and future prospects for, such techniques are discussed.