| Title |
Nitriding of Steels by Ion Implantation |
| Abstract |
Accelerated N＾+ ions were implanted into iron and steel to study the change of the mechanical properties which are sensitive to the surface. The hardness of tool steel (SKD 61) was increased by about 50% with implantation at dose of 5×10＾(16) N＾+ ions/㎝² at 50 keV beam energy. It was found that both the hardness and the fatigue life ware increased with increasing dose of N＾+ ions. A dry wear test conducted on pin-on-disc showed that the wear rate of implanted samples was greater than that of unimplanted ones due to the change in oxidation behavior with implantation, while the rate of running-in-wear was decreased by implantation under lubricated condition. Evidence from TEM supported the existence of nitride precipitates of particle size of 10-100 A˚at dislocations in implanted pure iron. SIMS analysis was employed to study the chemical composition of the implanted layer. |