Phase instabilities during Ti-nitride precipitation in nitrogen implanted Ti-6AI-4V alloy

Abstract

Grazing incidence X-ray diffraction, performed on a 70 keY nitrogen implanted Ti-6AI-4V system, reveals phase instabilities, during the course of nitride formation. With the build up of unbound N atom concentration, for a dose of I x 1016 ions/cm 2, the surface region becomes a-rich, whereas, on precipitation of Ti-nitrides at a high dose of I x 1017 ions/cm 2, the/]-Ti phase reappears, at the surface and beyond the implanted zone. The low concentration of V and the strain in the nitrided zone, have led to radiation induced martensitic transformation of the fl-Ti phase.