High temperature oxidation and hot corrosion behaviors of Ti2AlNb alloy at 923 K and 1023 K

Highlights: • High temperature oxidation behaviors of Ti₂AlNb alloy at 923 K and 1023 K were investigated. • Hot corrosion behaviors of Ti₂AlNb alloy at 923 K and 1023 K with different salt mixtures were investigated. • Ti₂AlNb alloy has good high temperature oxidation and hot corrosion resistance at 923 K. • Ti₂AlNb alloy was not resistant to corrosion in contact with the salt mixtures consisting of NaCl and Na₂SO₄ at 1023 K. • Ti₂AlNb alloy could not be used in oxidation environment at 1023 K for a long time. High temperature oxidation and hot corrosion behaviors of a Ti₂AlNb alloy (Ti₂AlNb) at 923 K and 1023 K for 1000 h were investigated, using mixtures of sodium chloride (NaCl) and sodium sulfate (Na₂SO₄) as the hot corrosion media. Mass gains of oxidation and mass changes of hot corrosion of the alloy were measured. Surface morphologies, cross-section structure and products of the alloy after oxidation and hot corrosion were examined and analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS). The alloy exhibited good high temperature oxidation resistance and hot corrosion resistance at 923 K over a period of 1000 h. The alloy was not resistant to oxidation and hot corrosion at 1023 K over the same period. The higher the content of NaCl in the mixed salt medium, the more intense was the hot corrosion of the alloy.