MeV ion implantation of N into Ti for surface hardening

The microstructural and hardening effects of MeV N+ ion implanted into Ti have been examined and compared to the results of hundred keV implantations. Rutherford backscattering spectrometry shows that concentrations of up to 50 at. % N are easily built up for μm depths in Ti targets. X-ray diffraction gives evidence for the formation of titanium nitride (TiN). An increase in surface hardness of 30% using loads as heavy as 100 g was observed in the MeV-implanted specimens, while no hardening effects could be detected using these loads in the case of implantations with about hundred keV energies. This discovery in which MeV N implantation can form hardened layers of μm thickness on metals with higher load-carrying ability than that of hundred keV implanted species should be able to extend the application scope of the N implantation technique in the metallurgical field