A Study Of N Ions Implantation On Surface Modification Of Two Types Of New Titanium Alloys

Titanium and titanium alloys are widely uesed in aviation, space technology and bioengineering because of their excellent properties, i.e, high yield strength, low density, good corrosion resistance and biocompatibility. However, more extensive utilization has been restricted by their poor surface properties, especially poor frictional characteristics. The research of surfaces modifying of titanium alloys is becoming a hot subject recently.As an important technique of Ti alloy surface hardness modification, nitriding of materials has been used widely. In this paper, the problems relevant to the technique of nitriding has been summarized. And based on those vies, the influence of N ions implantation on the structure and component of the titanium alloy Ti-4A1-2V and Ti-2Al-2.5Zr was studied.Ti-4A1-2V and Ti-2Al-2.5Zr alloy samples were implanted with 75keV N ions at a temperature of ²00℃. The N ions implantation injection dosages are 3×l0¹⁷cm^-2 and 8×10¹⁷cm^-2, respectively. The projected range calculated with TRIM 96 was about 1222 A|°. The results were analyzed using X-ray diffraction (XRD) and X-ray photoelectron spectrometer (XPS). The X-ray diffraction patterns showed that new phases TiN and TiO₂ were formed of after N⁺ ions implantation. XPS surveys between binding energies 0 to 1000 eV showed that there existed Ti, C, N and O. High-resolution XPS collections of the Ti_2p and N_1s binding energy showed that TiN and TiO₂ were formed after N ions implantation. The microhardness measurement showed that hardness of Ti-4Al-2V and Ti-2Al-2.5Zr alloy are endanced by 75keV nitrogen ion implantation.