A kinetics and morphological study on the oxidation behavior of Ti-4Al-2V Alloy

Abstract

Oxidation behavior of Ti–4Al–2V alloy in air was studied by isothermal thermogravimetry. It was found that the oxidation kinetics are parabolic in the temperature range 450–700 °C. The activation energies for reaction of titanium with oxygen and oxide growth were calculated as 90 and 114 kJ/mol, respectively. Microhardness measurements showed that thermal oxidation at 700 °C could increase the depth of subsurface diffusion zone up to 150 μm. The morphological studies of oxidized surfaces revealed that the thermal oxidation at 700 °C led to scaling and eventual detachment of the scale from the substrate due to the cracking at the metal/oxide interface.