Surface modification of Ti-4Al-2V alloy by nitrogen implantation

Ti-4Al-2V is a new type of alpha titanium alloy that suitable for the application in high-temperature and high-pressure water/steam environment. Ti-4Al-2V can be used in marine engineering, nuclear power industry. In this paper the surface characterization of the Ti-4Al-2V implanted with 75 keV nitrogen with fluences of 3 × 1017 and 8 × 1017 N+/cm2 is investigated by glancing-incidence XRD, XPS and microhardness. The results show that new phase TiN are formed after N implantation in the surface region. The nitrogen implantation increases the surface hardness up to 340 and 260% for fluence of 8 × 1017 and 3 × 1017 N+/cm2, respectively. The enhancement of hardness is related to the formation of TiN and irradiation induced hardness.