Composition depth profiles and the effects of annealing for ion- implanted alloys.
Avondale, MD: U.S. Department of the Interior, Bureau of Mines, RI 8387, 1979 Jan; :1-24
The Bureau of Mines is developing alloys using ion implantation as an alternative to bulk alloys that consume large quantities of strategic materials such as chromium and nickel. These alloys are formed at the outer layer of relatively common materials. To more fully understand the corrosion characteristics and physical properties of this outer layer, it was necessary to determine the alloy concentration as a function of depth into the substrate material. Also, since many of the ion-implanted alloys would be utilized at elevated temperatures, it was necessary to determine the diffusion behavior of the implanted element. Proton-induced x-ray emission and inert gas ion sputtering have been utilized to generate composition depth profiles for fe-cr, fe-ni, and fe-al ion implanted alloys fabricated by implanting 25-kev cr+, ni+, or al+ into iron substrates. The data were fitted (utilizing a computer program) with symmetrical Gaussian profiles yielding values for the range and range straggle of the ions. These parameters were then compared with those calculated from theory. Changes in the profiles due to annealing were investigated and values for the diffusion coefficient were obtained assuming diffusion according to fick's law. For the cr+ and ni+ implantation, the profiles as-implanted agree reasonably well with theory and exhibit "normal" diffusion chracteristics at 500 deg c. For the al+ implantation, the profile as-implanted is much broader than predicted and exhibits substantial enhanced diffusion at temperatures up to 500 deg c.
IH; Report of Investigations
NTIS Accession No.
Avondale, MD: U.S. Department of the Interior, Bureau of Mines, RI 8387