Oxidation Behavior of Additively Manufactured Ti-added FeCrAl Alloys

Additions of titanium nitrides (TiN) can reduce cracking sensitivity of FeCrAl alloys manufactured by laser powder bed fusion through grain refinement. However, the oxidation behavior of TiN-added FeCrAl alloys is not reported up to date. In the present work, high-temperature oxidation of additively manufactured (AM) FeCrAl alloys with Ti additions from 0.5 to 1.1 w.%. has been studied in air at 1250°C during 1000 h. The AM Ti-added FeCrAl alloys have shown a higher oxidation rate than their cast reference alloy. The degradation kinetics during high-temperature exposure of the model AM alloy are described and discussed with respect to the microstructural examination. The Ti addition is shown to affect the spallation kinetics. The formation of TiN precipitates at the metal/oxide interface and their growth within the alumina scale during the exposure at 1250°C was revealed for the first time in FeCrAl material.