Characterization of ion induced damage as a function of depth in proton irradiated pure Ti and Ti–6Al–4V

Abstract The inhomogeneous damage caused by ion irradiation (proton) as a function of depth has been characterized on pure Ti and Ti–6Al–4V at different doses. X-ray line profile analysis was used to evaluate the microstructural parameters such as domain size and microstrain within the domain. Although a systematic decrease in domain size as a function of depth is observed in both the materials, but the changes are less prominent in Ti–6Al–4V than in pure Ti. The increase in the value of S-parameters measured from Doppler Broadening Spectroscopy of Positron annihilation technique reveals higher concentration of open volume defects near Bragg peak (maximum damage region).Micro-hardness is also measured as a function of depth for both irradiated and unirradiated samples. The results obtained from microhardness measurements are found to corroborate with the findings from PAS and XRDLPA. Radiation induced segregation (RIS) which was observed in the Ti–6Al–4V at the highest dose 5E17p/cm2 is found to be limited near to the surface. Detailed X-ray analysis using Convolutional Multiple Whole Profile fitting of the XRD data from the surface of the irradiated Ti–6Al–4V samples could reveal the nature of the dislocations (i.e. or type).