Degradation of Ti–24Al–15Nb alloys under different environmental conditions

The present paper examines the degradation of titanium aluminide intermetallic,Ti–24Al–15Nb in three different environments which simulates acidic, marine and industrial environments at two temperatures. The titanium aluminide can form a protective oxide scale under marine and industrial environments at both low and high temperatures, while in acidic environments it can form a protective oxide scale at lower but not at higher temperatures. The corrosion rate evaluated in different environments and at different temperatures was found to increase by about two and half times in acidic environments and twice in marine and industrial environments when the temperature increases from 25 to 50 °C. The pitting corrosion studies in different environments revealed that the alloy is resistant to pitting and crevice corrosion in all the environments at higher temperatures but susceptible at lower temperatures in marine and industrial environments. Recommendations are made for the use of the alloy in components intended for use in a variety of industries.