Wear and corrosion resistance of Ti6Al4V alloy irradiated by high-intensity pulsed ion beam

Abstract

The high-intensity pulsed ion beam (HIPIB) technique has emerged as an efficient tool for surface engineering of materials. In this work, the Ti6Al4V alloy is irradiated by HIPIB at an accelerating pulse voltage of 300 kV in a pulse width of 75 ns (FWHM) with an ion current density ranging from 60 A/cm 2 to 250 A/cm 2 under one shot. The X-ray diffraction (XRD) analysis shows that the irradiated surface composed of α-Ti phase and β-Ti phase in minor amount retains the original structure of the Ti6Al4V alloy. The irradiated surfaces have an increased microhardness of about HV 0.25 N 4.1 GPa in the modified layers 150–750 μm thick, which depend on the ion current density of 60–250 A/cm 2. The wear tests are performed on a pin-on-disc tribometer in which the irradiated samples are rubbed against a hardened Cr12MoV high alloy steel disc (HRC 62–63) under a normal load of 18 N using machine oil as the lubricant media. The wear rate of the irradiated Ti6Al4V alloy is approximately reduced by 50–70%, compared with that of the non-irradiated alloy. The electrochemical polarization measurement shows that improved corrosion resistance of the irradiated Ti6Al4V alloy is obtained in 1 mol l − 1 HCl test solution. We proved that the HIPIB irradiation onto the Ti6Al4V alloy results in combined improvement in wear and corrosion resistance.