The electrochemical corrosion behaviour of Ti-48Al-2Nb-0.7Cr-0.3Si alloy in 3.5%NaCl

Abstract

Titanium aluminides (TiAl) have attracted industrial interest, particularly for high temperature applications owing to their promising mechanical properties. Due to the application of these materials to the marine environment it is therefore important to understand their performance under such conditions. In this study, the corrosion behaviour of Ti-48Al-2Nb-0.7Cr-0.3Si alloy produced by vacuum arc melting was investigated using the potentiodynamic polarization method. The corroded surface and Ti-Al phases were investigated by scanning electron microscopy (SEM), optical microscopy, and X-ray diffraction (XRD). Hardness was examined by a Vickers micro hardness tester with a diamond indenter. Pitting was observed to occur within the surface defects and caused severe corrosion.