High temperature oxidation behaviour of V-Ti-Ta alloys

摘要

The high temperature oxidation behavior of V and V-4Ti-(1-7) Ta alloys was investigated under air atmosphere in the temperature range from 250 to 750 degrees C using isothermal oxidation testing. The oxidized samples were characterized with Grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM-EDS). Oxidation kinetics of the investigated samples at different temperatures (250, 300 and 500 degrees C) have been established. The activation energies for oxidation were estimated for V, V-4Ti-(1-7)Ta alloys and compared with reference V-4Cr-4Ti alloy. V-4Ti-7Ta alloy exhibited 20% lesser weight gain compared to V-4Cr-4Ti alloy. The improved oxidation performance of V-Ti-Ta alloys was attributed to decreased activity of vanadium in V-Ti-Ta alloy. Ta increases the activation energy for oxygen diffusion in V-Ti-Ta alloys, which contributes to enhance the oxidation performance of the alloys.