Tribological Characteristics of Nitrogen (N₊) Implanted Iron

Abstract

The effect of implantation of nitrogen ions (1.5 MeV) on the friction and wear characteristics of pure iron sliding against M-50 steel (unimplanted) was studied in a pin-on-disk sliding friction apparatus. Test conditions included room temperature (∼25°C), a dry air atmosphere, a load of ½ kg (4.9 N), sliding velocities of 0.043 to 0.078 m/s (∼15 to 25 rpm), a pure hydrocarbon lubricant (n-hexadecane), or a USP mineral oil and nitrogen ion implantation doses of 5 × 10¹⁵ and 5 × 10¹⁷ ions/cm².

No differences in wear rates were observed in the low-dose (5 × 10¹⁵ ions/cm²) experiments. In the high-dose experiments (5 × 10¹⁷ ions/cm²), small reductions in initial (∼40 percent) and steady-state (∼20 percent) wear rates were observed for nitrogen-implanted iron riders as compared with unimplanted controls. No differences in average friction coefficients were noted for either dose.

Auger electron spectroscopy combined with argon ion bombardment revealed a subsurface Gaussian nitrogen distribution with a maximum concentration of 6 atomic percent at a depth of 8 × 10⁻⁷ m (0.8 μm). Similar analysis within the wear scar (∼2.0 × 10⁻⁵ m subsurface) of an implanted rider after 20 μm of wear yielded only background nitrogen concentration. No inward migration of nitrogen ions was observed.

Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in Washington, D.C., October 5–7, 1982

Notes

Presented as an American Society of Lubrication Engineers paper at the ASME/ASLE Lubrication Conference in Washington, D.C., October 5–7, 1982